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 9fa78b8a237acad26dcd4510c16d764746f6edcf..e53a18ac296e07ff7e763c81d837fe58d8f44aab 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 1.151 2003/03/10 03:53:50 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.152 2003/03/13 16:58:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1489,13 +1489,14 @@ make_groupsortplan(Query *parse,
                   Plan *subplan)
 {
    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;
 
        /*
@@ -1509,6 +1510,7 @@ make_groupsortplan(Query *parse,
            resdom->reskey = ++keyno;
            resdom->reskeyop = grpcl->sortop;
        }
+       grpno++;
    }
 
    Assert(keyno > 0);