Modify hash_search() API to prevent future occurrences of the error

spotted by Qingqing Zhou.  The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places.  If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL.  But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/timezone/pgtz.c b/src/timezone/pgtz.c
index bdf3d404079..38c71964065 100644
--- a/src/timezone/pgtz.c
+++ b/src/timezone/pgtz.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.31 2005/05/23 21:54:02 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.32 2005/05/29 04:23:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -971,6 +971,7 @@ identify_system_timezone(void)
  * load and parse the TZ definition file every time it is selected.
  */
 static HTAB *timezone_cache = NULL;
+
 static bool
 init_timezone_hashtable(void)
 {
@@ -1013,14 +1014,18 @@ pg_tzset(const char *name)
 							  HASH_FIND,
 							  NULL);
 	if (tzp)
+	{
 		/* Timezone found in cache, nothing more to do */
 		return tzp;
+	}
 
 	if (tzload(name, &tz.state) != 0)
 	{
 		if (name[0] == ':' || tzparse(name, &tz.state, FALSE) != 0)
+		{
 			/* Unknown timezone. Fail our call instead of loading GMT! */
 			return NULL;
+		}
 	}
 
 	strcpy(tz.TZname, name);
@@ -1031,9 +1036,6 @@ pg_tzset(const char *name)
 					  HASH_ENTER,
 					  NULL);
 	
-	if (!tzp)
-		return NULL;
-	
 	strcpy(tzp->TZname, tz.TZname);
 	memcpy(&tzp->state, &tz.state, sizeof(tz.state));