Yawn ... still another place not quite ready for zero-column tables.

diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index b703bf2b86e095c81dcc95435f32e7f16334ca3e..25dfc2611e8ab9466ba31a2b750fd2d3c4f7d3b2 100644 (file)
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.109 2004/04/07 18:17:25 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.110 2004/05/11 22:43:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -264,8 +264,11 @@ generate_union_plan(SetOperationStmt *op, Query *parse,
                List       *sortList;
 
                sortList = addAllTargetsToSortList(NULL, NIL, tlist, false);
-               plan = (Plan *) make_sort_from_sortclauses(parse, sortList, plan);
-               plan = (Plan *) make_unique(plan, sortList);
+               if (sortList)
+               {
+                       plan = (Plan *) make_sort_from_sortclauses(parse, sortList, plan);
+                       plan = (Plan *) make_unique(plan, sortList);
+               }
                *sortClauses = sortList;
        }
        else
@@ -324,6 +327,13 @@ generate_nonunion_plan(SetOperationStmt *op, Query *parse,
         * correct output.
         */
        sortList = addAllTargetsToSortList(NULL, NIL, tlist, false);
+
+       if (sortList == NIL)            /* nothing to sort on? */
+       {
+               *sortClauses = NIL;
+               return plan;
+       }
+
        plan = (Plan *) make_sort_from_sortclauses(parse, sortList, plan);
        switch (op->op)
        {
@@ -519,9 +529,9 @@ generate_append_tlist(List *colTypes, bool flag,
         * First extract typmods to use.
         *
         * If the inputs all agree on type and typmod of a particular column, use
-        * that typmod; else use -1.
+        * that typmod; else use -1.  (+1 here in case of zero columns.)
         */
-       colTypmods = (int32 *) palloc(length(colTypes) * sizeof(int32));
+       colTypmods = (int32 *) palloc(length(colTypes) * sizeof(int32) + 1);
 
        foreach(planl, input_plans)
        {