BUG24659561: Fix MySQLCursor.executemany() when using utf8mb4 charset

Inserting multiple rows into a table will fail with a LookupError when
using a connection with utf8mb4 charset.

This patch changes the charset used in MySQLCursor.executemany() to
the Python charset for current connection.

A test case was added for regression.

Author: nmariz

lib/mysql/connector/cursor.py

@@ -589,11 +589,11 @@ def remove_comments(match):
                 "Failed rewriting statement for multi-row INSERT. "
                 "Check SQL syntax."
             )
-        fmt = matches.group(1).encode(self._connection.charset)
+        fmt = matches.group(1).encode(self._connection.python_charset)
         values = []
 
         try:
-            stmt = operation.encode(self._connection.charset)
+            stmt = operation.encode(self._connection.python_charset)
             for params in seq_params:
                 tmp = fmt
                 if isinstance(params, dict):

tests/test_bugs.py

@@ -4460,3 +4460,27 @@ def test_cmd_query_iter(self):
             results.append(result)
             if "columns" in result:
                 results.append(self.cnx.get_rows())
+
+
+class BugOra24659561(tests.MySQLConnectorTests):
+    """BUG#24659561: LOOKUPERROR: UNKNOWN ENCODING: UTF8MB4
+    """
+    def setUp(self):
+        config = tests.get_mysql_config()
+        config["charset"] = "utf8mb4"
+        self.tbl = "BugOra24659561"
+        self.cnx = connection.MySQLConnection(**config)
+        self.cur = self.cnx.cursor()
+        self.cur.execute("DROP TABLE IF EXISTS {0}".format(self.tbl))
+        self.cur.execute("CREATE TABLE {0} (id INT, name VARCHAR(100))"
+                         "".format(self.tbl))
+
+    def tearDown(self):
+        self.cur.execute("DROP TABLE IF EXISTS {0}".format(self.tbl))
+        self.cur.close()
+
+    def test_executemany_utf8mb4(self):
+        self.cur.executemany(
+            "INSERT INTO {0} VALUES (%s, %s)".format(self.tbl),
+            [(1, "Nuno"), (2, "Amitabh"), (3, "Rafael")]
+        )