Enable fallback to string type when argument(s) are of UNKNOWN type.

 Same code exactly as for function resolution.
 An obvious example is for
  select '1' = '01';
 which used to throw an error and which now resolves to two text strings.

diff --git a/src/backend/parser/parse_oper.c b/src/backend/parser/parse_oper.c
index 73be990c01083f0f070f174621ac422d38674396..7b30131251e1c4027bfbbfee4f676ea11e80e004 100644 (file)
--- a/src/backend/parser/parse_oper.c
+++ b/src/backend/parser/parse_oper.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.41 2000/05/28 17:56:00 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/parser/parse_oper.c,v 1.42 2000/11/07 16:01:01 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -443,8 +443,21 @@ oper_select_candidate(int nargs,
                }
                else if (current_category != slot_category)
                {
-                   /* punt if more than one category for this slot */
-                   return NULL;
+                   /* started out as unknown type, so give preference to string type, if available */
+                   if (current_category == STRING_TYPE)
+                   {
+                       /* forget all previous candidates */
+                       candidates = current_candidate;
+                       last_candidate = current_candidate;
+                   }
+                   else if (slot_category == STRING_TYPE)
+                   {
+                       /* forget this candidate */
+                       if (last_candidate)
+                           last_candidate->next = current_candidate->next;
+                       else
+                           candidates = current_candidate->next;
+                   }
                }
                else if (current_type != slot_type)
                {