added empty string support for enum, added test

Author: idop-alooma

Diff for: pymysqlreplication/column.py

@@ -72,7 +72,7 @@ def __read_string_metadata(self, packet, column_schema):
     def __read_enum_metadata(self, column_schema):
         enums = column_schema["COLUMN_TYPE"]
         if self.type == FIELD_TYPE.ENUM:
-            self.enum_values = enums.replace('enum(', '')\
+            self.enum_values = [''] + enums.replace('enum(', '')\
                 .replace(')', '').replace('\'', '').split(',')
         else:
             self.set_values = enums.replace('set(', '')\

Diff for: pymysqlreplication/row_event.py

@@ -162,7 +162,7 @@ def _read_column_data(self,  cols_bitmap):
                 values[name] = self.packet.read_uint8() + 1900
             elif column.type == FIELD_TYPE.ENUM:
                 values[name] = column.enum_values[
-                    self.packet.read_uint_by_size(column.size) - 1]
+                    self.packet.read_uint_by_size(column.size)]
             elif column.type == FIELD_TYPE.SET:
                 # We read set columns as a bitmap telling us which options
                 # are enabled

Diff for: pymysqlreplication/tests/test_data_type.py

@@ -378,6 +378,18 @@ def test_enum(self):
         self.assertEqual(event.rows[0]["values"]["test"], 'ba')
         self.assertEqual(event.rows[0]["values"]["test2"], 'a')
 
+    def test_enum_empty_string(self):
+        create_query = "CREATE TABLE test (test ENUM('a', 'ba', 'c'), test2 ENUM('a', 'ba', 'c')) CHARACTER SET latin1 COLLATE latin1_bin;"
+        insert_query = "INSERT INTO test VALUES('ba', 'asdf')"
+        last_sql_mode = self.execute("SELECT @@SESSION.sql_mode;"). \
+            fetchall()[0][0]
+        self.execute("SET SESSION sql_mode = 'ANSI';")
+        event = self.create_and_insert_value(create_query, insert_query)
+        self.execute("SET SESSION sql_mode = '%s';" % last_sql_mode)
+
+        self.assertEqual(event.rows[0]["values"]["test"], 'ba')
+        self.assertEqual(event.rows[0]["values"]["test2"], '')
+
     def test_set(self):
         create_query = "CREATE TABLE test (test SET('a', 'ba', 'c'), test2 SET('a', 'ba', 'c')) CHARACTER SET latin1 COLLATE latin1_bin;"
         insert_query = "INSERT INTO test VALUES('ba,a,c', 'a,c')"