*** pgsql/src/backend/optimizer/path/allpaths.c	2009/02/15 20:16:21	1.180
--- pgsql/src/backend/optimizer/path/allpaths.c	2009/03/10 20:58:26	1.181
***************
*** 8,14 ****
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.179 2009/01/01 17:23:43 momjian Exp $
   *
   *-------------------------------------------------------------------------
   */
--- 8,14 ----
   *
   *
   * IDENTIFICATION
!  *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.180 2009/02/15 20:16:21 tgl Exp $
   *
   *-------------------------------------------------------------------------
   */
*************** set_subquery_pathlist(PlannerInfo *root,
*** 523,528 ****
--- 523,535 ----
  	PlannerInfo *subroot;
  	List	   *pathkeys;
  
+ 	/*
+ 	 * Must copy the Query so that planning doesn't mess up the RTE contents
+ 	 * (really really need to fix the planner to not scribble on its input,
+ 	 * someday).
+ 	 */
+ 	subquery = copyObject(subquery);
+ 
  	/* We need a workspace for keeping track of set-op type coercions */
  	differentTypes = (bool *)
  		palloc0((list_length(subquery->targetList) + 1) * sizeof(bool));