Fix merging pathes of pruned rels ("indices are unused" problem).

diff --git a/src/backend/optimizer/path/prune.c b/src/backend/optimizer/path/prune.c
index 014c72e90605b483ef875e3374309856fcafd46a..250a670fc43eb354fed7ac0c75eff505144f62cf 100644 (file)
--- a/src/backend/optimizer/path/prune.c
+++ b/src/backend/optimizer/path/prune.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/prune.c,v 1.12 1998/02/26 04:32:43 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/optimizer/path/Attic/prune.c,v 1.13 1998/04/02 07:27:15 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -61,39 +61,25 @@ prune_joinrels(List *rel_list)
 static List *
 prune_joinrel(Rel *rel, List *other_rels)
 {
-   List       *cur = NIL;
-   List       *return_list = NIL;
+   List       *i = NIL;
+   List       *result = NIL;
 
-   /* find first relation that doesn't match */
-   foreach(cur, other_rels)
+   foreach(i, other_rels)
    {
-       Rel        *other_rel = (Rel *) lfirst(cur);
-
-       if (!same(rel->relids, other_rel->relids))
-           break;
-   }
-
-   /* we now know cur doesn't match, or is NIL */
-   return_list = cur;
-
-   /*
-    * remove relations that do match, we use lnext so we can remove
-    * easily
-    */
-   while (cur != NIL && lnext(cur) != NIL)
-   {
-       Rel        *other_rel = (Rel *) lfirst(lnext(cur));
-
+       Rel    *other_rel = (Rel *) lfirst(i);
+       
        if (same(rel->relids, other_rel->relids))
        {
            rel->pathlist = add_pathlist(rel,
                                         rel->pathlist,
                                         other_rel->pathlist);
-           lnext(cur) = lnext(lnext(cur));     /* delete it */
        }
-       cur = lnext(cur);
+       else
+       {
+           result = nconc(result, lcons(other_rel, NIL));
+       }
    }
-   return return_list;
+   return (result);
 }
 
 /*