From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 18 Oct 2014 02:33:14 +0000 (-0400)
Subject: Avoid core dump in _outPathInfo() for Path without a parent RelOptInfo.
X-Git-Tag: REL9_1_15~88
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=96139cfbbc1581d6f17b601b37ce9dda88d36322;p=thirdparty%2Fpostgresql.git

Avoid core dump in _outPathInfo() for Path without a parent RelOptInfo.

Nearly all Paths have parents, but a ResultPath representing an empty FROM
clause does not.  Avoid a core dump in such cases.  I believe this is only
a hazard for debugging usage, not for production, else we'd have heard
about it before.  Nonetheless, back-patch to 9.1 where the troublesome code
was introduced.  Noted while poking at bug #11703.
---

diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index cd6c275c639..01b2d6d2d4a 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1466,7 +1466,10 @@ _outPathInfo(StringInfo str, Path *node)
 {
 	WRITE_ENUM_FIELD(pathtype, NodeTag);
 	appendStringInfo(str, " :parent_relids ");
-	_outBitmapset(str, node->parent->relids);
+	if (node->parent)
+		_outBitmapset(str, node->parent->relids);
+	else
+		_outBitmapset(str, NULL);
 	WRITE_FLOAT_FIELD(startup_cost, "%.2f");
 	WRITE_FLOAT_FIELD(total_cost, "%.2f");
 	WRITE_NODE_FIELD(pathkeys);