Repair oversight in 8.2 change that improved the handling of "pseudoconstant"

WHERE clauses.  createplan.c is now willing to stick a gating Result node
almost anywhere in the plan tree, and in particular one can wind up directly
underneath a MergeJoin node.  This means it had better be willing to handle
Mark/Restore.  Fortunately, that's trivial in such cases, since we can just
pass off the call to the input node (which the planner has previously ensured
can handle Mark/Restore).  Per report from Phil Frost.

2 files changed, 52 insertions, 4 deletions

diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index 1d5246f9ecd..6a9bd773056 100644
--- a/src/backend/executor/execAmi.c
+++ b/src/backend/executor/execAmi.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/executor/execAmi.c,v 1.89 2006/08/02 01:59:45 joe Exp $
+ *	$PostgreSQL: pgsql/src/backend/executor/execAmi.c,v 1.89.2.1 2007/02/15 03:07:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -243,6 +243,10 @@ ExecMarkPos(PlanState *node)
 			ExecSortMarkPos((SortState *) node);
 			break;
 
+		case T_ResultState:
+			ExecResultMarkPos((ResultState *) node);
+			break;
+
 		default:
 			/* don't make hard error unless caller asks to restore... */
 			elog(DEBUG2, "unrecognized node type: %d", (int) nodeTag(node));
@@ -296,6 +300,10 @@ ExecRestrPos(PlanState *node)
 			ExecSortRestrPos((SortState *) node);
 			break;
 
+		case T_ResultState:
+			ExecResultRestrPos((ResultState *) node);
+			break;
+
 		default:
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
 			break;
@@ -328,6 +336,16 @@ ExecSupportsMarkRestore(NodeTag plantype)
 		case T_Sort:
 			return true;
 
+		case T_Result:
+			/*
+			 * T_Result only supports mark/restore if it has a child plan
+			 * that does, so we do not have enough information to give a
+			 * really correct answer.  However, for current uses it's
+			 * enough to always say "false", because this routine is not
+			 * asked about gating Result plans, only base-case Results.
+			 */
+			return false;
+
 		default:
 			break;
 	}
diff --git a/src/backend/executor/nodeResult.c b/src/backend/executor/nodeResult.c
index a0c18cf3658..c698daa317b 100644
--- a/src/backend/executor/nodeResult.c
+++ b/src/backend/executor/nodeResult.c
@@ -38,7 +38,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.34.2.2 2007/02/02 00:07:28 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.34.2.3 2007/02/15 03:07:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -167,6 +167,36 @@ ExecResult(ResultState *node)
 }
 
 /* ----------------------------------------------------------------
+ *		ExecResultMarkPos
+ * ----------------------------------------------------------------
+ */
+void
+ExecResultMarkPos(ResultState *node)
+{
+	PlanState  *outerPlan = outerPlanState(node);
+
+	if (outerPlan != NULL)
+		ExecMarkPos(outerPlan);
+	else
+		elog(DEBUG2, "Result nodes do not support mark/restore");
+}
+
+/* ----------------------------------------------------------------
+ *		ExecResultRestrPos
+ * ----------------------------------------------------------------
+ */
+void
+ExecResultRestrPos(ResultState *node)
+{
+	PlanState  *outerPlan = outerPlanState(node);
+
+	if (outerPlan != NULL)
+		ExecRestrPos(outerPlan);
+	else
+		elog(ERROR, "Result nodes do not support mark/restore");
+}
+
+/* ----------------------------------------------------------------
  *		ExecInitResult
  *
  *		Creates the run-time state information for the result node
@@ -180,8 +210,8 @@ ExecInitResult(Result *node, EState *estate, int eflags)
 	ResultState *resstate;
 
 	/* check for unsupported flags */
-	Assert(!(eflags & EXEC_FLAG_MARK));
-	Assert(!(eflags & EXEC_FLAG_BACKWARD) || outerPlan(node) != NULL);
+	Assert(!(eflags & (EXEC_FLAG_MARK | EXEC_FLAG_BACKWARD)) ||
+		   outerPlan(node) != NULL);
 
 	/*
 	 * create state structure