1 files changed, 4 insertions, 71 deletions

diff --git a/src/backend/executor/execScan.c b/src/backend/executor/execScan.c
index 5dfc49deb95..837abc0f017 100644
--- a/src/backend/executor/execScan.c
+++ b/src/backend/executor/execScan.c
@@ -23,8 +23,6 @@
 #include "utils/memutils.h"
 
 
-static bool tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc);
-
 
 /*
  * ExecScanFetch -- check interrupts & fetch next potential tuple
@@ -237,8 +235,9 @@ void
 ExecAssignScanProjectionInfo(ScanState *node)
 {
 	Scan	   *scan = (Scan *) node->ps.plan;
+	TupleDesc	tupdesc = node->ss_ScanTupleSlot->tts_tupleDescriptor;
 
-	ExecAssignScanProjectionInfoWithVarno(node, scan->scanrelid);
+	ExecConditionalAssignProjectionInfo(&node->ps, tupdesc, scan->scanrelid);
 }
 
 /*
@@ -248,75 +247,9 @@ ExecAssignScanProjectionInfo(ScanState *node)
 void
 ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno)
 {
-	Scan	   *scan = (Scan *) node->ps.plan;
-
-	if (tlist_matches_tupdesc(&node->ps,
-							  scan->plan.targetlist,
-							  varno,
-							  node->ss_ScanTupleSlot->tts_tupleDescriptor))
-		node->ps.ps_ProjInfo = NULL;
-	else
-		ExecAssignProjectionInfo(&node->ps,
-								 node->ss_ScanTupleSlot->tts_tupleDescriptor);
-}
-
-static bool
-tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc)
-{
-	int			numattrs = tupdesc->natts;
-	int			attrno;
-	bool		hasoid;
-	ListCell   *tlist_item = list_head(tlist);
-
-	/* Check the tlist attributes */
-	for (attrno = 1; attrno <= numattrs; attrno++)
-	{
-		Form_pg_attribute att_tup = TupleDescAttr(tupdesc, attrno - 1);
-		Var		   *var;
-
-		if (tlist_item == NULL)
-			return false;		/* tlist too short */
-		var = (Var *) ((TargetEntry *) lfirst(tlist_item))->expr;
-		if (!var || !IsA(var, Var))
-			return false;		/* tlist item not a Var */
-		/* if these Asserts fail, planner messed up */
-		Assert(var->varno == varno);
-		Assert(var->varlevelsup == 0);
-		if (var->varattno != attrno)
-			return false;		/* out of order */
-		if (att_tup->attisdropped)
-			return false;		/* table contains dropped columns */
-
-		/*
-		 * Note: usually the Var's type should match the tupdesc exactly, but
-		 * in situations involving unions of columns that have different
-		 * typmods, the Var may have come from above the union and hence have
-		 * typmod -1.  This is a legitimate situation since the Var still
-		 * describes the column, just not as exactly as the tupdesc does. We
-		 * could change the planner to prevent it, but it'd then insert
-		 * projection steps just to convert from specific typmod to typmod -1,
-		 * which is pretty silly.
-		 */
-		if (var->vartype != att_tup->atttypid ||
-			(var->vartypmod != att_tup->atttypmod &&
-			 var->vartypmod != -1))
-			return false;		/* type mismatch */
-
-		tlist_item = lnext(tlist_item);
-	}
-
-	if (tlist_item)
-		return false;			/* tlist too long */
-
-	/*
-	 * If the plan context requires a particular hasoid setting, then that has
-	 * to match, too.
-	 */
-	if (ExecContextForcesOids(ps, &hasoid) &&
-		hasoid != tupdesc->tdhasoid)
-		return false;
+	TupleDesc	tupdesc = node->ss_ScanTupleSlot->tts_tupleDescriptor;
 
-	return true;
+	ExecConditionalAssignProjectionInfo(&node->ps, tupdesc, varno);
 }
 
 /*