Adjust string comparison so that only bitwise-equal strings are considered

equal: if strcoll claims two strings are equal, check it with strcmp, and
sort according to strcmp if not identical.  This fixes inconsistent
behavior under glibc's hu_HU locale, and probably under some other locales
as well.  Also, take advantage of the now-well-defined behavior to speed up
texteq, textne, bpchareq, bpcharne: they may as well just do a bitwise
comparison and not bother with strcoll at all.

NOTE: affected databases may need to REINDEX indexes on text columns to be
sure they are self-consistent.

1 files changed, 10 insertions, 1 deletions

diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index d4276ac1015..15261f3248d 100644
--- a/src/backend/utils/adt/varlena.c
+++ b/src/backend/utils/adt/varlena.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.92.2.3 2004/02/01 04:05:13 joe Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.92.2.4 2005/12/22 22:50:29 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -760,6 +760,15 @@ varstr_cmp(char *arg1, int len1, char *arg2, int len2)
 
 		result = strcoll(a1p, a2p);
 
+		/*
+		 * In some locales strcoll() can claim that nonidentical strings are
+		 * equal.  Believing that would be bad news for a number of reasons,
+		 * so we follow Perl's lead and sort "equal" strings according to
+		 * strcmp().
+		 */
+		if (result == 0)
+			result = strcmp(a1p, a2p);
+
 		pfree(a1p);
 		pfree(a2p);
 	}