From 31b255318ded2547a9dbc0425768e9bb14427aaa Mon Sep 17 00:00:00 2001
From: Mitsuru Hasegawa <hasegawa@metrosystems.co.jp>
Date: Wed, 8 Aug 2012 20:27:44 +0900
Subject: [PATCH] =?utf8?q?Bug=20fix:EXECUTE=E3=82=B3=E3=83=9E=E3=83=B3?=
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EXECUTEコマンド実行時に、ProcessUtility_hookの初期処理で外部変数に
ステートメント名を保存し、終了処理でNULLに戻すが、ProcessUtility_hook
の実行中にエラー終了した場合は、外部変数にステートメント名が設定
されたままだった。
このため、その後SELECT等の通常のクエリを発行すると、外部変数に
残っているステートメント名を使用して、プランキャッシュからクエリ
文字列を取得し、その文字列に指定されているヒントを使用していた。
---
 Makefile                 |  4 ++++
 expected/prepare-9.1.out | 18 ++++++++++++++++++
 expected/prepare-9.2.out | 18 ++++++++++++++++++
 pg_hint_plan.c           | 16 ++++++++++++++++
 sql/prepare.sql          |  2 ++
 5 files changed, 58 insertions(+)

diff --git a/Makefile b/Makefile
index 81080cd..c342956 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,10 @@
 MODULES = pg_hint_plan
 REGRESS = init base_plan pg_hint_plan prepare fdw
 
+ifdef UNIT_TEST
+PG_CPPFLAGS = -O0
+endif
+
 EXTRA_CLEAN = sql/fdw.sql expected/base_plan.out expected/prepare.out expected/fdw.out
 
 PG_CONFIG = pg_config
diff --git a/expected/prepare-9.1.out b/expected/prepare-9.1.out
index 66fb6ab..08e095d 100644
--- a/expected/prepare-9.1.out
+++ b/expected/prepare-9.1.out
@@ -653,3 +653,21 @@ EXPLAIN (COSTS false) EXECUTE p7 (10);
 /*+ NestLoop(t1 t2) */
 EXPLAIN (COSTS false) EXECUTE p8 (10);
 ERROR:  prepared statement "p8" does not exist
+/*+ NestLoop(t1 t2) */
+EXPLAIN (COSTS false) SELECT count(*) FROM t1, t2 WHERE t1.id = t2.id AND t1.id > 10;
+LOG:  pg_hint_plan:
+used hint:
+NestLoop(t1 t2)
+not used hint:
+duplication hint:
+error hint:
+
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Aggregate
+   ->  Nested Loop
+         ->  Seq Scan on t2
+         ->  Index Scan using t1_pkey on t1
+               Index Cond: ((id > 10) AND (id = t2.id))
+(5 rows)
+
diff --git a/expected/prepare-9.2.out b/expected/prepare-9.2.out
index ed55e2a..62f25b4 100644
--- a/expected/prepare-9.2.out
+++ b/expected/prepare-9.2.out
@@ -818,3 +818,21 @@ EXPLAIN (COSTS false) EXECUTE p7 (10);
 /*+ NestLoop(t1 t2) */
 EXPLAIN (COSTS false) EXECUTE p8 (10);
 ERROR:  prepared statement "p8" does not exist
+/*+ NestLoop(t1 t2) */
+EXPLAIN (COSTS false) SELECT count(*) FROM t1, t2 WHERE t1.id = t2.id AND t1.id > 10;
+LOG:  pg_hint_plan:
+used hint:
+NestLoop(t1 t2)
+not used hint:
+duplication hint:
+error hint:
+
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Aggregate
+   ->  Nested Loop
+         ->  Seq Scan on t2
+         ->  Index Scan using t1_pkey on t1
+               Index Cond: ((id > 10) AND (id = t2.id))
+(5 rows)
+
diff --git a/pg_hint_plan.c b/pg_hint_plan.c
index fd8743a..5ae0c30 100644
--- a/pg_hint_plan.c
+++ b/pg_hint_plan.c
@@ -1384,11 +1384,18 @@ set_join_config_options(unsigned char enforce_mask, GucContext context)
  */
 
 static void
+ProcessUtility_hook_error_callback(void *arg)
+{
+	stmt_name = NULL;
+}
+
+static void
 pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
 							ParamListInfo params, bool isTopLevel,
 							DestReceiver *dest, char *completionTag)
 {
 	Node				   *node;
+	ErrorContextCallback	errcontext;
 
 	if (!pg_hint_plan_enable)
 	{
@@ -1428,6 +1435,12 @@ pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
 	{
 		ExecuteStmt	   *stmt;
 
+		/* Set up callback to statement name reset. */
+		errcontext.callback = ProcessUtility_hook_error_callback;
+		errcontext.arg = NULL;
+		errcontext.previous = error_context_stack;
+		error_context_stack = &errcontext;
+
 		stmt = (ExecuteStmt *) node;
 		stmt_name = stmt->name;
 	}
@@ -1442,6 +1455,9 @@ pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
 	if (stmt_name)
 	{
 		stmt_name = NULL;
+
+		/* Remove error callback. */
+		error_context_stack = errcontext.previous;
 	}
 }
 
diff --git a/sql/prepare.sql b/sql/prepare.sql
index 26d69a3..e10d776 100644
--- a/sql/prepare.sql
+++ b/sql/prepare.sql
@@ -127,3 +127,5 @@ EXPLAIN (COSTS false) EXECUTE p7 (10);
 -- error case
 /*+ NestLoop(t1 t2) */
 EXPLAIN (COSTS false) EXECUTE p8 (10);
+/*+ NestLoop(t1 t2) */
+EXPLAIN (COSTS false) SELECT count(*) FROM t1, t2 WHERE t1.id = t2.id AND t1.id > 10;
-- 
2.11.0