From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 1 Feb 2021 17:30:19 +0200
Subject: [PATCH v3 4/5] Fix bugs in the commit to change conversion function
 signature.

Per John Naylor's report, and some bugs I found while testing.

TODO: to be squashed.
---
 src/backend/utils/mb/conv.c                      | 16 ++++++----------
 .../utf8_and_iso8859_1/utf8_and_iso8859_1.c      |  8 ++++++++
 src/backend/utils/mb/mbutils.c                   |  5 +++--
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/backend/utils/mb/conv.c b/src/backend/utils/mb/conv.c
index b83358bc7a5..f3bda5753d0 100644
--- a/src/backend/utils/mb/conv.c
+++ b/src/backend/utils/mb/conv.c
@@ -497,7 +497,6 @@ UtfToLocal(const unsigned char *utf, int len,
 	int			l;
 	const pg_utf_to_local_combined *cp;
 	const unsigned char *start = utf;
-	const unsigned char *cur = utf;
 
 	if (!PG_VALID_ENCODING(encoding))
 		ereport(ERROR,
@@ -511,8 +510,6 @@ UtfToLocal(const unsigned char *utf, int len,
 		unsigned char b3 = 0;
 		unsigned char b4 = 0;
 
-		cur = iso;
-
 		/* "break" cases all represent errors */
 		if (*utf == '\0')
 			break;
@@ -648,10 +645,11 @@ UtfToLocal(const unsigned char *utf, int len,
 		}
 
 		/* failed to translate this character */
+		utf -= l;
 		if (noError)
 			break;
 		report_untranslatable_char(PG_UTF8, encoding,
-								   (const char *) (utf - l), len);
+								   (const char *) utf, len);
 	}
 
 	/* if we broke out of loop early, must be invalid input */
@@ -660,7 +658,7 @@ UtfToLocal(const unsigned char *utf, int len,
 
 	*iso = '\0';
 
-	return cur - start;
+	return utf - start;
 }
 
 /*
@@ -701,7 +699,6 @@ LocalToUtf(const unsigned char *iso, int len,
 	int			l;
 	const pg_local_to_utf_combined *cp;
 	const unsigned char *start = iso;
-	const unsigned char *cur = iso;
 
 	if (!PG_VALID_ENCODING(encoding))
 		ereport(ERROR,
@@ -715,8 +712,6 @@ LocalToUtf(const unsigned char *iso, int len,
 		unsigned char b3 = 0;
 		unsigned char b4 = 0;
 
-		cur = iso;
-
 		/* "break" cases all represent errors */
 		if (*iso == '\0')
 			break;
@@ -799,10 +794,11 @@ LocalToUtf(const unsigned char *iso, int len,
 		}
 
 		/* failed to translate this character */
+		iso -= l;
 		if (noError)
 			break;
 		report_untranslatable_char(encoding, PG_UTF8,
-								   (const char *) (iso - l), len);
+								   (const char *) iso, len);
 	}
 
 	/* if we broke out of loop early, must be invalid input */
@@ -811,5 +807,5 @@ LocalToUtf(const unsigned char *iso, int len,
 
 	*utf = '\0';
 
-	return cur - start;
+	return iso - start;
 }
diff --git a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
index 8ac93604a1b..d0dc4cca378 100644
--- a/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
+++ b/src/backend/utils/mb/conversion_procs/utf8_and_iso8859_1/utf8_and_iso8859_1.c
@@ -104,10 +104,18 @@ utf8_to_iso8859_1(PG_FUNCTION_ARGS)
 			int			l = pg_utf_mblen(src);
 
 			if (l > len || !pg_utf8_islegal(src, l))
+			{
+				if (noError)
+					break;
 				report_invalid_encoding(PG_UTF8, (const char *) src, len);
+			}
 			if (l != 2)
+			{
+				if (noError)
+					break;
 				report_untranslatable_char(PG_UTF8, PG_LATIN1,
 										   (const char *) src, len);
+			}
 			c1 = src[1] & 0x3f;
 			c = ((c & 0x1f) << 6) | c1;
 			if (c >= 0x80 && c <= 0xff)
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 3e106027d75..af1cafe523a 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -818,12 +818,13 @@ perform_default_encoding_conversion(const char *src, int len,
 		MemoryContextAllocHuge(CurrentMemoryContext,
 							   (Size) len * MAX_CONVERSION_GROWTH + 1);
 
-	FunctionCall5(flinfo,
+	FunctionCall6(flinfo,
 				  Int32GetDatum(src_encoding),
 				  Int32GetDatum(dest_encoding),
 				  CStringGetDatum(src),
 				  CStringGetDatum(result),
-				  Int32GetDatum(len));
+				  Int32GetDatum(len),
+				  BoolGetDatum(false));
 
 	/*
 	 * Release extra space if there might be a lot --- see comments in
-- 
2.29.2


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