1 files changed, 29 insertions, 19 deletions

diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c
index 1585da0d0e1..fdcc62096cf 100644
--- a/src/backend/utils/adt/varbit.c
+++ b/src/backend/utils/adt/varbit.c
@@ -20,6 +20,7 @@
 #include "common/int.h"
 #include "libpq/pqformat.h"
 #include "nodes/nodeFuncs.h"
+#include "nodes/supportnodes.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/varbit.h"
@@ -672,32 +673,41 @@ varbit_send(PG_FUNCTION_ARGS)
 }
 
 /*
- * varbit_transform()
- * Flatten calls to varbit's length coercion function that set the new maximum
- * length >= the previous maximum length.  We can ignore the isExplicit
- * argument, since that only affects truncation cases.
+ * varbit_support()
+ *
+ * Planner support function for the varbit() length coercion function.
+ *
+ * Currently, the only interesting thing we can do is flatten calls that set
+ * the new maximum length >= the previous maximum length.  We can ignore the
+ * isExplicit argument, since that only affects truncation cases.
  */
 Datum
-varbit_transform(PG_FUNCTION_ARGS)
+varbit_support(PG_FUNCTION_ARGS)
 {
-	FuncExpr   *expr = castNode(FuncExpr, PG_GETARG_POINTER(0));
+	Node	   *rawreq = (Node *) PG_GETARG_POINTER(0);
 	Node	   *ret = NULL;
-	Node	   *typmod;
 
-	Assert(list_length(expr->args) >= 2);
+	if (IsA(rawreq, SupportRequestSimplify))
+	{
+		SupportRequestSimplify *req = (SupportRequestSimplify *) rawreq;
+		FuncExpr   *expr = req->fcall;
+		Node	   *typmod;
 
-	typmod = (Node *) lsecond(expr->args);
+		Assert(list_length(expr->args) >= 2);
 
-	if (IsA(typmod, Const) &&!((Const *) typmod)->constisnull)
-	{
-		Node	   *source = (Node *) linitial(expr->args);
-		int32		new_typmod = DatumGetInt32(((Const *) typmod)->constvalue);
-		int32		old_max = exprTypmod(source);
-		int32		new_max = new_typmod;
-
-		/* Note: varbit() treats typmod 0 as invalid, so we do too */
-		if (new_max <= 0 || (old_max > 0 && old_max <= new_max))
-			ret = relabel_to_typmod(source, new_typmod);
+		typmod = (Node *) lsecond(expr->args);
+
+		if (IsA(typmod, Const) &&!((Const *) typmod)->constisnull)
+		{
+			Node	   *source = (Node *) linitial(expr->args);
+			int32		new_typmod = DatumGetInt32(((Const *) typmod)->constvalue);
+			int32		old_max = exprTypmod(source);
+			int32		new_max = new_typmod;
+
+			/* Note: varbit() treats typmod 0 as invalid, so we do too */
+			if (new_max <= 0 || (old_max > 0 && old_max <= new_max))
+				ret = relabel_to_typmod(source, new_typmod);
+		}
 	}
 
 	PG_RETURN_POINTER(ret);