From b86b7767f9f3facc0869d9f1bc4304dce954e8a9 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <ishii@sraoss.co.jp>
Date: Fri, 25 Nov 2022 16:33:17 +0900
Subject: [PATCH] Fix ROLLBACK TO command to work in aborted transaction.

Commit:

https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commit;h=eea522ebfcf791a623e865deaa1aa6fb59e3c50b

fixed some cases in aborted transaction so that SQL commands except
COMMIT/ROLLBACK are not forwarded to backend. But it missed ROLLBACK
TO command. As a result even if ROLLBACK TO command is issued, the
command was not forwarded to backend and the transaction keeps on in
aborted state.
Back patched through 4.3 which the commit was brought in.
Also add a test case for ROLLBACK TO to test 078.
Discussion:
https://www.pgpool.net/pipermail/pgpool-general-jp/2022-November/001715.html
---
 src/include/protocol/pool_proto_modules.h      |  1 +
 src/protocol/pool_process_query.c              | 17 ++++++++++++++++-
 src/protocol/pool_proto_modules.c              |  2 +-
 .../tests/078.aborted_transaction/expected.txt | 18 ++++++++++++++++++
 .../tests/078.aborted_transaction/test.sh      |  6 ++++++
 5 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/include/protocol/pool_proto_modules.h b/src/include/protocol/pool_proto_modules.h
index 1fd6f8c68..57280a3e3 100644
--- a/src/include/protocol/pool_proto_modules.h
+++ b/src/include/protocol/pool_proto_modules.h
@@ -153,6 +153,7 @@ extern bool is_select_query(Node *node, char *sql);
 extern bool is_commit_query(Node *node);
 extern bool is_rollback_query(Node *node);
 extern bool is_commit_or_rollback_query(Node *node);
+extern bool is_rollback_to_query(Node *node);
 extern bool is_strict_query(Node *node);	/* returns non 0 if this is strict
 											 * query */
 extern int	need_insert_lock(POOL_CONNECTION_POOL * backend, char *query, Node *node);
diff --git a/src/protocol/pool_process_query.c b/src/protocol/pool_process_query.c
index 8d1c0c819..f2db65eab 100644
--- a/src/protocol/pool_process_query.c
+++ b/src/protocol/pool_process_query.c
@@ -1246,7 +1246,7 @@ is_select_query(Node *node, char *sql)
 bool
 is_commit_or_rollback_query(Node *node)
 {
-	return is_commit_query(node) || is_rollback_query(node);
+	return is_commit_query(node) || is_rollback_query(node) || is_rollback_to_query(node);
 }
 
 /*
@@ -1281,6 +1281,21 @@ is_rollback_query(Node *node)
 	return stmt->kind == TRANS_STMT_ROLLBACK;
 }
 
+/*
+ * Returns true if SQL is transaction rollback to command
+ */
+bool
+is_rollback_to_query(Node *node)
+{
+	TransactionStmt *stmt;
+
+	if (node == NULL || !IsA(node, TransactionStmt))
+		return false;
+
+	stmt = (TransactionStmt *) node;
+	return stmt->kind == TRANS_STMT_ROLLBACK_TO;
+}
+
 /*
  * send error message to frontend
  */
diff --git a/src/protocol/pool_proto_modules.c b/src/protocol/pool_proto_modules.c
index a20aa6922..255cc4fad 100644
--- a/src/protocol/pool_proto_modules.c
+++ b/src/protocol/pool_proto_modules.c
@@ -310,7 +310,7 @@ SimpleQuery(POOL_CONNECTION * frontend,
 		/*
 		 * Check if the transaction is in abort status. If so, we do nothing
 		 * and just return an error message to frontend, execpt for
-		 * transaction commit or abort command.
+		 * transaction COMMIT or ROLLBACK (TO) command.
 		 */
 		if (check_transaction_state_and_abort(contents, node, frontend, backend) == false)
 		{
diff --git a/src/test/regression/tests/078.aborted_transaction/expected.txt b/src/test/regression/tests/078.aborted_transaction/expected.txt
index be37381b4..f70e6716e 100644
--- a/src/test/regression/tests/078.aborted_transaction/expected.txt
+++ b/src/test/regression/tests/078.aborted_transaction/expected.txt
@@ -26,3 +26,21 @@ SELECT 1;
         1
 (1 row)
 
+BEGIN;
+BEGIN
+SAVEPOINT s1;
+SAVEPOINT
+aaa;
+ERROR:  syntax error at or near "aaa"
+LINE 1: aaa;
+        ^
+ROLLBACK TO s1;
+ROLLBACK
+SELECT 1;
+ ?column? 
+----------
+        1
+(1 row)
+
+END;
+COMMIT
diff --git a/src/test/regression/tests/078.aborted_transaction/test.sh b/src/test/regression/tests/078.aborted_transaction/test.sh
index 47bd280c1..7c8eca387 100755
--- a/src/test/regression/tests/078.aborted_transaction/test.sh
+++ b/src/test/regression/tests/078.aborted_transaction/test.sh
@@ -33,6 +33,12 @@ aaa;
 SELECT 1;
 END;
 SELECT 1;
+BEGIN;
+SAVEPOINT s1;
+aaa;
+ROLLBACK TO s1;
+SELECT 1;
+END;
 EOF
 
 if cmp ../expected.txt results.txt >/dev/null
-- 
2.39.5