GROUP BY got confused if there were multiple equal() GROUP BY items.

This bug has been latent since 7.0 or maybe even further back, but it
was only exposed when parse_clause.c stopped suppressing duplicate
items (see its rev 1.96 of 18-Aug-02).

diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index c759f6e2503d7f2fdb4eaa21e92f22c514cdf34e..91071977a492b8a87171128bf00318110fb08431 100644 (file)
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.125.2.2 2003/03/05 18:38:26 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.125.2.3 2003/03/13 16:58:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1498,13 +1498,14 @@ make_groupplan(Query *parse,
         * are just dummies with no extra execution cost.)
         */
        List       *sort_tlist = new_unsorted_tlist(subplan->targetlist);
+       int         grpno = 0;
        int         keyno = 0;
        List       *gl;
 
        foreach(gl, groupClause)
        {
            GroupClause *grpcl = (GroupClause *) lfirst(gl);
-           TargetEntry *te = nth(grpColIdx[keyno] - 1, sort_tlist);
+           TargetEntry *te = nth(grpColIdx[grpno] - 1, sort_tlist);
            Resdom     *resdom = te->resdom;
 
            /*
@@ -1518,6 +1519,7 @@ make_groupplan(Query *parse,
                resdom->reskey = ++keyno;
                resdom->reskeyop = grpcl->sortop;
            }
+           grpno++;
        }
 
        Assert(keyno > 0);