Fix for CONPY-246:

Rollback transaction if connection pool was created with
pool_reset_connection=False.

mariadb/connectionpool.py

@@ -19,9 +19,9 @@
 
 import mariadb
 import _thread
+from mariadb.constants import STATUS
 
 MAX_POOL_SIZE = 64
-POOL_IDLE_TIMEOUT = 1800
 
 
 class ConnectionPool(object):
@@ -193,9 +193,12 @@ class ConnectionPool(object):
         by connection object.
         """
 
-        with self._lock_pool:
         if self._pool_args["reset_connection"]:
             connection.reset()
+        elif connection.server_status & STATUS.IN_TRANS:
+            connection.rollback()
+
+        with self._lock_pool:
 
             for i in range(0, len(self._connections_used)):
                 if self._connections_used[i] == connection:

testing/test/integration/test_pooling.py

@@ -36,6 +36,30 @@ class TestPooling(unittest.TestCase):
         except mariadb.ProgrammingError:
             pass
 
+    def test_conpy246(self):
+        # test if a pooled connection will be roll backed
+
+        default_conf = conf()
+
+        pool = mariadb.ConnectionPool(pool_name="CONPY246",
+                                      pool_size=1,
+                                      pool_reset_connection=False,
+                                      **default_conf)
+        conn = pool.get_connection()
+        cursor = conn.cursor()
+        cursor.execute("CREATE OR REPLACE TABLE conpy246(a int)")
+        cursor.execute("INSERT INTO conpy246 VALUES (1)")
+        cursor.close()
+        conn.close()
+        conn = pool.get_connection()
+        cursor = conn.cursor()
+        cursor.execute("SELECT * FROM conpy246")
+        self.assertEqual(cursor.rowcount, 0)
+        cursor.execute("DROP TABLE conpy246")
+        cursor.close()
+        conn.close()
+        pool.close()
+
     def test_conpy245(self):
         # we can't test performance here, but we can check if LRU works.
         # All connections must have been used the same number of times.