From 996f793d5470b73c946af6f61dce6ff37a3d2890 Mon Sep 17 00:00:00 2001
From: Brian Cloutier <github@briancloutier.com>
Date: Thu, 27 Oct 2016 17:18:53 +0300
Subject: [PATCH] Copy raw_parse_tree before using it

Address citusdata/citus#922.

Fixes a segfault in PG's installcheck caused by our reuse of
raw_parse_tree when handling EXPLAIN EXECUTE.
---
 src/backend/distributed/executor/multi_utility.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/backend/distributed/executor/multi_utility.c b/src/backend/distributed/executor/multi_utility.c
index 890b8f992..8f4917459 100644
--- a/src/backend/distributed/executor/multi_utility.c
+++ b/src/backend/distributed/executor/multi_utility.c
@@ -313,6 +313,7 @@ multi_ProcessUtility(Node *parsetree,
 			ExecuteStmt *execstmt = (ExecuteStmt *) query->utilityStmt;
 			PreparedStatement *entry = FetchPreparedStatement(execstmt->name, true);
 			CachedPlanSource *plansource = entry->plansource;
+			Node *parseTreeCopy;
 			Query *originalQuery;
 
 			/* copied from ExplainExecuteQuery, will never trigger if you used PREPARE */
@@ -322,7 +323,9 @@ multi_ProcessUtility(Node *parsetree,
 									   " cached plans")));
 			}
 
-			originalQuery = parse_analyze(plansource->raw_parse_tree,
+			parseTreeCopy = copyObject(plansource->raw_parse_tree);
+
+			originalQuery = parse_analyze(parseTreeCopy,
 										  plansource->query_string,
 										  plansource->param_types,
 										  plansource->num_params);