Klugy fix for bug #2447: we can't expand a whole-row reference to NEW

in a rule WHERE expression while inserting it into the original query,
because the 8.0 ResolveNew API is wrongly designed.  This is fixed in 8.1
but I'm disinclined to risk back-porting the changes.  Instead, just stop
the coredump and instead issue the same 'cannot handle whole-row reference'
message that 7.4 and before generated in this situation.

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 4bc66db0bc03cd03e80622d071b152ec76847d3d..a9843f0d823db6956935ac2ed16714a2069e4ae7 100644 (file)
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.147 2004/12/31 22:00:45 pgsql Exp $
+ *   $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.147.4.1 2006/05/23 17:09:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1046,7 +1046,7 @@ CopyAndAddInvertedQual(Query *parsetree,
        new_qual = ResolveNew(new_qual,
                              PRS2_NEW_VARNO,
                              0,
-                             parsetree->rtable,
+                             NIL,              /* fix bug #2447 */
                              parsetree->targetList,
                              event,
                              rt_index);

diff --git a/src/backend/rewrite/rewriteManip.c b/src/backend/rewrite/rewriteManip.c
index 75e1fb562e9e2494fc83df44539410a9d535f72c..9542848ac0cdec8153a325408b892ab482a45951 100644 (file)
--- a/src/backend/rewrite/rewriteManip.c
+++ b/src/backend/rewrite/rewriteManip.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/rewrite/rewriteManip.c,v 1.89.4.1 2006/01/06 20:11:24 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/rewrite/rewriteManip.c,v 1.89.4.2 2006/05/23 17:09:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -942,6 +942,24 @@ ResolveNew_mutator(Node *node, ResolveNew_context *context)
                RowExpr    *rowexpr;
                List       *fields;
 
+               /*
+                * Klugy fix for bug #2447: we can't expand a whole-row
+                * reference to "NEW" in a rule WHERE expression while
+                * inserting it into the original query, because its varno
+                * will be PRS2_NEW_VARNO which is not the rtindex of the RTE
+                * we should use.  The 8.0 ResolveNew API is wrongly designed.
+                * We aren't going to try to back-port the 8.1 API, just avoid
+                * crashing.  (This never worked before 8.0, either.)
+                * CopyAndAddInvertedQual passes NIL for target_rtable, so
+                * testing for NIL would be sufficient, but let's put in a
+                * full check on the rtindex for safety.
+                */
+               if (this_varno < 1 ||
+                   this_varno > list_length(context->target_rtable))
+                   ereport(ERROR,
+                           (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                            errmsg("cannot handle whole-row reference")));
+
                /*
                 * If generating an expansion for a var of a named rowtype
                 * (ie, this is a plain relation RTE), then we must