From ad004ce7876ea2998c9c13007c7dd3dd8f9ffcad Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 4 Sep 2006 18:32:55 +0000
Subject: [PATCH] Change ILIKE to invoke lower() and then do plain LIKE
comparison when working in a multibyte encoding. This fixes the problems
exhibited in bug #1931 and other reports of ILIKE misbehavior in UTF8
encoding. It's a pretty grotty solution though --- should rethink how to do
it after we install better locale support, someday.
---
src/backend/utils/adt/like.c | 163 +++++++++++++++++++++--------------
1 file changed, 100 insertions(+), 63 deletions(-)
diff --git a/src/backend/utils/adt/like.c b/src/backend/utils/adt/like.c
index 4037c28a609..e2026218bf5 100644
--- a/src/backend/utils/adt/like.c
+++ b/src/backend/utils/adt/like.c
@@ -11,7 +11,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/like.c,v 1.64 2006/03/05 15:58:42 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/like.c,v 1.65 2006/09/04 18:32:55 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -64,50 +64,23 @@ wchareq(char *p1, char *p2)
return 1;
}
-/*--------------------
- * Support routine for MatchTextIC. Compares given multibyte streams
- * as wide characters ignoring case.
- * If they match, returns 1 otherwise returns 0.
- *--------------------
+/*
+ * Formerly we had a routine iwchareq() here that tried to do case-insensitive
+ * comparison of multibyte characters. It did not work at all, however,
+ * because it relied on tolower() which has a single-byte API ... and
+ * towlower() wouldn't be much better since we have no suitably cheap way
+ * of getting a single character transformed to the system's wchar_t format.
+ * So now, we just downcase the strings using lower() and apply regular LIKE
+ * comparison. This should be revisited when we install better locale support.
+ *
+ * Note that MBMatchText and MBMatchTextIC do exactly the same thing now.
+ * Is it worth refactoring to avoid duplicated code? They might become
+ * different again in the future.
*/
-#define CHARMAX 0x80
-
-static int
-iwchareq(char *p1, char *p2)
-{
- pg_wchar c1[2],
- c2[2];
- int l;
-
- /*
- * short cut. if *p1 and *p2 is lower than CHARMAX, then we could assume
- * they are ASCII
- */
- if ((unsigned char) *p1 < CHARMAX && (unsigned char) *p2 < CHARMAX)
- return (tolower((unsigned char) *p1) == tolower((unsigned char) *p2));
-
- /*
- * if one of them is an ASCII while the other is not, then they must be
- * different characters
- */
- else if ((unsigned char) *p1 < CHARMAX || (unsigned char) *p2 < CHARMAX)
- return 0;
-
- /*
- * ok, p1 and p2 are both > CHARMAX, then they must be multibyte
- * characters
- */
- l = pg_mblen(p1);
- (void) pg_mb2wchar_with_len(p1, c1, l);
- c1[0] = tolower(c1[0]);
- l = pg_mblen(p2);
- (void) pg_mb2wchar_with_len(p2, c2, l);
- c2[0] = tolower(c2[0]);
- return (c1[0] == c2[0]);
-}
+/* Set up to compile like_match.c for multibyte characters */
#define CHAREQ(p1, p2) wchareq(p1, p2)
-#define ICHAREQ(p1, p2) iwchareq(p1, p2)
+#define ICHAREQ(p1, p2) wchareq(p1, p2)
#define NextChar(p, plen) \
do { int __l = pg_mblen(p); (p) +=__l; (plen) -=__l; } while (0)
#define CopyAdvChar(dst, src, srclen) \
@@ -120,7 +93,9 @@ iwchareq(char *p1, char *p2)
#define MatchText MBMatchText
#define MatchTextIC MBMatchTextIC
#define do_like_escape MB_do_like_escape
+
#include "like_match.c"
+
#undef CHAREQ
#undef ICHAREQ
#undef NextChar
@@ -129,15 +104,19 @@ iwchareq(char *p1, char *p2)
#undef MatchTextIC
#undef do_like_escape
+/* Set up to compile like_match.c for single-byte characters */
#define CHAREQ(p1, p2) (*(p1) == *(p2))
#define ICHAREQ(p1, p2) (tolower((unsigned char) *(p1)) == tolower((unsigned char) *(p2)))
#define NextChar(p, plen) ((p)++, (plen)--)
#define CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
+#include "like_match.c"
+
+/* And some support for BYTEA */
#define BYTEA_CHAREQ(p1, p2) (*(p1) == *(p2))
#define BYTEA_NextChar(p, plen) ((p)++, (plen)--)
#define BYTEA_CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
-#include "like_match.c"
+
/*
* interface routines called by the function manager
@@ -296,15 +275,32 @@ nameiclike(PG_FUNCTION_ARGS)
int slen,
plen;
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat) - VARHDRSZ);
-
if (pg_database_encoding_max_length() == 1)
+ {
+ s = NameStr(*str);
+ slen = strlen(s);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
+ }
else
+ {
+ /* Force inputs to lower case to achieve case insensitivity */
+ text *strtext;
+
+ strtext = DatumGetTextP(DirectFunctionCall1(name_text,
+ NameGetDatum(str)));
+ strtext = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(strtext)));
+ pat = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(pat)));
+
+ s = VARDATA(strtext);
+ slen = (VARSIZE(strtext) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MBMatchTextIC(s, slen, p, plen) == LIKE_TRUE);
+ }
PG_RETURN_BOOL(result);
}
@@ -320,15 +316,32 @@ nameicnlike(PG_FUNCTION_ARGS)
int slen,
plen;
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat) - VARHDRSZ);
-
if (pg_database_encoding_max_length() == 1)
+ {
+ s = NameStr(*str);
+ slen = strlen(s);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) != LIKE_TRUE);
+ }
else
+ {
+ /* Force inputs to lower case to achieve case insensitivity */
+ text *strtext;
+
+ strtext = DatumGetTextP(DirectFunctionCall1(name_text,
+ NameGetDatum(str)));
+ strtext = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(strtext)));
+ pat = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(pat)));
+
+ s = VARDATA(strtext);
+ slen = (VARSIZE(strtext) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MBMatchTextIC(s, slen, p, plen) != LIKE_TRUE);
+ }
PG_RETURN_BOOL(result);
}
@@ -344,15 +357,27 @@ texticlike(PG_FUNCTION_ARGS)
int slen,
plen;
- s = VARDATA(str);
- slen = (VARSIZE(str) - VARHDRSZ);
- p = VARDATA(pat);
- plen = (VARSIZE(pat) - VARHDRSZ);
-
if (pg_database_encoding_max_length() == 1)
+ {
+ s = VARDATA(str);
+ slen = (VARSIZE(str) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
+ }
else
+ {
+ /* Force inputs to lower case to achieve case insensitivity */
+ str = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(str)));
+ pat = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(pat)));
+ s = VARDATA(str);
+ slen = (VARSIZE(str) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MBMatchTextIC(s, slen, p, plen) == LIKE_TRUE);
+ }
PG_RETURN_BOOL(result);
}
@@ -368,15 +393,27 @@ texticnlike(PG_FUNCTION_ARGS)
int slen,
plen;
- s = VARDATA(str);
- slen = (VARSIZE(str) - VARHDRSZ);
- p = VARDATA(pat);
- plen = (VARSIZE(pat) - VARHDRSZ);
-
if (pg_database_encoding_max_length() == 1)
+ {
+ s = VARDATA(str);
+ slen = (VARSIZE(str) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) != LIKE_TRUE);
+ }
else
+ {
+ /* Force inputs to lower case to achieve case insensitivity */
+ str = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(str)));
+ pat = DatumGetTextP(DirectFunctionCall1(lower,
+ PointerGetDatum(pat)));
+ s = VARDATA(str);
+ slen = (VARSIZE(str) - VARHDRSZ);
+ p = VARDATA(pat);
+ plen = (VARSIZE(pat) - VARHDRSZ);
result = (MBMatchTextIC(s, slen, p, plen) != LIKE_TRUE);
+ }
PG_RETURN_BOOL(result);
}
--
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