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[PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
45+ messages / 2 participants
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* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-03 12:00  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-03 12:00 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

copyreadline we would incorrectly interpret the sequence as an end-of-copy
marker (\.). this can only happen in encodings that can "embed" ascii
characters as the second byte. one example of such sequence is
'\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.
---
 src/backend/commands/copyfromparse.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 798e18e013..c20ec482db 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,17 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * In principle, we would need to use pg_encoding_mblen() to
+				 * skip over the character in some encodings, like at the end
+				 * of the loop.  But if it's a multi-byte character, it cannot
+				 * have any special meaning and skipping isn't necessary for
+				 * correctness.  We can fall through to process it normally
+				 * instead.
 				 */
-				raw_buf_ptr++;
+				if (!IS_HIGHBIT_SET(c2))
+					raw_buf_ptr++;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------97F3138F3612F1A4F9200D93--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing.
@ 2021-02-04 19:36  Heikki Linnakangas <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Heikki Linnakangas @ 2021-02-04 19:36 UTC (permalink / raw)

If a multi-byte character is escaped with a backslash in TEXT mode input,
we didn't always treat the escape correctly. If:

- a multi-byte character is escaped with a backslash, and
- the second byte of the character is 0x5C, i.e. the ASCII code of a
  backslash (\), and
- the next character is a dot (.), then

CopyReadLineText function would incorrectly interpret the sequence as an
end-of-copy marker (\.). This can only happen in encodings that can
"embed" ascii characters as the second byte. One example of such sequence
is '\x5ca45c2e666f6f' in Big5 encoding. If you put that in a file, and
load it with COPY FROM, you'd incorrectly get an "end-of-copy marker
corrupt" error.

Backpatch to all supported versions.

Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
---
 src/backend/commands/copyfromparse.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index b843d315b1..315b16fd7a 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -1084,7 +1084,7 @@ CopyReadLineText(CopyFromState cstate)
 				break;
 			}
 			else if (!cstate->opts.csv_mode)
-
+			{
 				/*
 				 * If we are here, it means we found a backslash followed by
 				 * something other than a period.  In non-CSV mode, anything
@@ -1095,8 +1095,16 @@ CopyReadLineText(CopyFromState cstate)
 				 * backslashes are not special, so we want to process the
 				 * character after the backslash just like a normal character,
 				 * so we don't increment in those cases.
+				 *
+				 * Set 'c' to skip whole character correctly in multi-byte
+				 * encodings.  If we don't have the whole character in the
+				 * buffer yet, we might loop back to process it, after all,
+				 * but that's OK because multi-byte characters cannot have any
+				 * special meaning.
 				 */
 				raw_buf_ptr++;
+				c = c2;
+			}
 		}
 
 		/*
-- 
2.30.0


--------------CFC80B40DFDD66DF067F288D--





^ permalink  raw  reply  [nested|flat] 45+ messages in thread

* Clear padding in PgStat_HashKey keys
@ 2024-11-03 04:25  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Bertrand Drouvot @ 2024-11-03 04:25 UTC (permalink / raw)
  To: [email protected]

Hi hackers,

While working on a rebase for [0], I noticed some weird behavior on the stats.

The issue is that [0], in conjonction with b14e9ce7d5, does introduce padding in 
the PgStat_HashKey:

(gdb) ptype /o struct PgStat_HashKey
/* offset      |    size */  type = struct PgStat_HashKey {
/*      0      |       4 */    uint32 kind;
/*      4      |       4 */    Oid dboid;
/*      8      |       8 */    uint64 objid;
/*     16      |       4 */    RelFileNumber relfile;
/* XXX  4-byte padding   */

                               /* total size (bytes):   24 */
                             }

But, the keys are initialized that way:

"
PgStat_HashKey key = {.kind = kind,.dboid = dboid,.objid = objid,.relfile = refile};
"

which could lead to random data in the padding bytes.

We are using sizeof(PgStat_HashKey) in pgstat_cmp_hash_key() and we compute the
hash hash key in pgstat_hash_hash_key() using the PgStat_HashKey struct size as
input: this lead to unexpected results if the keys contain random data in the 
padding bytes.

Even if currently there is no issues, as without [0] there is no padding:

(gdb) ptype /o struct PgStat_HashKey
/* offset      |    size */  type = struct PgStat_HashKey {
/*      0      |       4 */    uint32 kind;
/*      4      |       4 */    Oid dboid;
/*      8      |       8 */    uint64 objid;

                               /* total size (bytes):   16 */
                             }

I think that we should ensure to $SUBJECT (to prevent unexpected results should
padding be introduced in the future).

For example we currently ensure the same for LOCALLOCKTAG localtag in LockHeldByMe()
while there is no padding:

gdb) ptype /o struct LOCALLOCKTAG
/* offset      |    size */  type = struct LOCALLOCKTAG {
/*      0      |      16 */    LOCKTAG lock;
/*     16      |       4 */    LOCKMODE mode;

                               /* total size (bytes):   20 */
                             }

So, please find attached a patch to $SUBJECT.

[0]: https://www.postgresql.org/message-id/flat/ZlGYokUIlERemvpB%40ip-10-97-1-34.eu-west-3.compute.intern...

Looking forward to your feedback,

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com


Attachments:

  [text/x-diff] v1-0001-Clear-padding-in-PgStat_HashKey-keys.patch (2.6K, ../../[email protected]/2-v1-0001-Clear-padding-in-PgStat_HashKey-keys.patch)
  download | inline diff:
From 0a590aad0ff014dff60e5ee73bef2c5d7a659804 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <[email protected]>
Date: Sat, 2 Nov 2024 14:21:18 +0000
Subject: [PATCH v1] Clear padding in PgStat_HashKey keys

PgStat_HashKey keys are currently initialized in a way that could result in random
data in the padding bytes (if there was padding in PgStat_HashKey which is not
the case currently).

We are using sizeof(PgStat_HashKey) in pgstat_cmp_hash_key() and we compute the
hash hash key in pgstat_hash_hash_key() using the PgStat_HashKey struct size as
input. So, we have to ensure that no random data can be stored in the padding
bytes (if any) of a PgStat_HashKey key.
---
 src/backend/utils/activity/pgstat.c       |  3 +++
 src/backend/utils/activity/pgstat_shmem.c | 18 ++++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)
 100.0% src/backend/utils/activity/

diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index be48432cc3..ea8c5691e8 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -938,6 +938,9 @@ pgstat_fetch_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
 
 	pgstat_prep_snapshot();
 
+	/* clear padding */
+	memset(&key, 0, sizeof(struct PgStat_HashKey));
+
 	key.kind = kind;
 	key.dboid = dboid;
 	key.objid = objid;
diff --git a/src/backend/utils/activity/pgstat_shmem.c b/src/backend/utils/activity/pgstat_shmem.c
index a09c6fee05..c1b7ff76b1 100644
--- a/src/backend/utils/activity/pgstat_shmem.c
+++ b/src/backend/utils/activity/pgstat_shmem.c
@@ -432,11 +432,18 @@ PgStat_EntryRef *
 pgstat_get_entry_ref(PgStat_Kind kind, Oid dboid, uint64 objid, bool create,
 					 bool *created_entry)
 {
-	PgStat_HashKey key = {.kind = kind,.dboid = dboid,.objid = objid};
+	PgStat_HashKey key;
 	PgStatShared_HashEntry *shhashent;
 	PgStatShared_Common *shheader = NULL;
 	PgStat_EntryRef *entry_ref;
 
+	/* clear padding */
+	memset(&key, 0, sizeof(struct PgStat_HashKey));
+
+	key.kind = kind;
+	key.dboid = dboid;
+	key.objid = objid;
+
 	/*
 	 * passing in created_entry only makes sense if we possibly could create
 	 * entry.
@@ -908,10 +915,17 @@ pgstat_drop_database_and_contents(Oid dboid)
 bool
 pgstat_drop_entry(PgStat_Kind kind, Oid dboid, uint64 objid)
 {
-	PgStat_HashKey key = {.kind = kind,.dboid = dboid,.objid = objid};
+	PgStat_HashKey key;
 	PgStatShared_HashEntry *shent;
 	bool		freed = true;
 
+	/* clear padding */
+	memset(&key, 0, sizeof(struct PgStat_HashKey));
+
+	key.kind = kind;
+	key.dboid = dboid;
+	key.objid = objid;
+
 	/* delete local reference */
 	if (pgStatEntryRefHash)
 	{
-- 
2.34.1



^ permalink  raw  reply  [nested|flat] 45+ messages in thread


end of thread, other threads:[~2024-11-03 04:25 UTC | newest]

Thread overview: 45+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-03 12:00 [PATCH 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2021-02-04 19:36 [PATCH v2 1/1] Fix a corner-case in COPY FROM backslash processing. Heikki Linnakangas <[email protected]>
2024-11-03 04:25 Clear padding in PgStat_HashKey keys Bertrand Drouvot <[email protected]>

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