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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

* vac_truncate_clog()'s bogus check leads to bogusness
@ 2023-06-21 22:12 Andres Freund <[email protected]>
  0 siblings, 0 replies; 45+ messages in thread

From: Andres Freund @ 2023-06-21 22:12 UTC (permalink / raw)
  To: pgsql-hackers; Noah Misch <[email protected]>

Hi,

When vac_truncate_clog() returns early, due to one of these paths:

	/*
	 * Do not truncate CLOG if we seem to have suffered wraparound already;
	 * the computed minimum XID might be bogus.  This case should now be
	 * impossible due to the defenses in GetNewTransactionId, but we keep the
	 * test anyway.
	 */
	if (frozenAlreadyWrapped)
	{
		ereport(WARNING,
				(errmsg("some databases have not been vacuumed in over 2 billion transactions"),
				 errdetail("You might have already suffered transaction-wraparound data loss.")));
		return;
	}

	/* chicken out if data is bogus in any other way */
	if (bogus)
		return;

we haven't released the lwlock that we acquired earlier:

	/* Restrict task to one backend per cluster; see SimpleLruTruncate(). */
	LWLockAcquire(WrapLimitsVacuumLock, LW_EXCLUSIVE);

as this isn't a path raising an error, the lock isn't released during abort.
Until there's some cause for the session to call LWLockReleaseAll(), the lock
is held. Until then neither the process holding the lock, nor any other
process, can finish vacuuming.  We don't even have an assert against a
self-deadlock with an already held lock, oddly enough.


This is somewhat nasty - there's no real way to get out of this without an
immediate restart, and it's hard to pinpoint the problem as well :(.


Ok, the subject line is not the most precise, but it was just too good an
opportunity.


To reproduce (only on a throwaway system please!):

CREATE DATABASE invalid;
UPDATE pg_database SET datfrozenxid = '10002' WHERE datname = 'invalid';
DROP TABLE IF EXISTS foo_tbl; CREATE TABLE foo_tbl(); DROP TABLE foo_tbl; VACUUM FREEZE;
DROP TABLE IF EXISTS foo_tbl; CREATE TABLE foo_tbl(); DROP TABLE foo_tbl; VACUUM FREEZE;
<hang>


Found this while writing a test for the fix for partial dropping of
databases [1].


Separately, I think it's quite bad that we *silently* return from
vac_truncate_clog() when finding a bogus xid. That's a quite severe condition,
we should at least tell the user about it.


Greetings,

Andres Freund

[1] https://postgr.es/m/20230621190204.nsaelabojxppiuix%40awork3.anarazel.de






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


end of thread, other threads:[~2023-06-21 22:12 UTC | newest]

Thread overview: 45+ messages (download: mbox mbox.gz follow: Atom feed)
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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]>
2023-06-21 22:12 vac_truncate_clog()'s bogus check leads to bogusness Andres Freund <[email protected]>

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