Replace strncpy with strlcpy in selected places that seem possibly relevant

to performance.  (A wholesale effort to get rid of strncpy should be
undertaken sometime, but not during beta.)  This commit also fixes dynahash.c
to correctly truncate overlength string keys for hashtables, so that its
callers don't have to anymore.

src/backend/utils/fmgr/dfmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.89 2006/08/16 04:32:48 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/fmgr/dfmgr.c,v 1.90 2006/09/27 18:40:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -594,7 +594,6 @@ find_rendezvous_variable(const char *varName)
 {
 	static HTAB         *rendezvousHash = NULL;
 
-	char			     key[NAMEDATALEN];
 	rendezvousHashEntry *hentry;
 	bool				 found;
 
@@ -612,12 +611,9 @@ find_rendezvous_variable(const char *varName)
 									 HASH_ELEM);
 	}
 
-	/* Turn the varName into a fixed-size string */
-	StrNCpy(key, varName, sizeof(key));
-
 	/* Find or create the hashtable entry for this varName */
 	hentry = (rendezvousHashEntry *) hash_search(rendezvousHash,
-												 key,
+												 varName,
 												 HASH_ENTER,
 												 &found);