Raise an explanatory exception when binary logging is not enabled. (#245)

Author: joeportela

pymysqlreplication/binlogstream.py

@@ -15,6 +15,7 @@
     XidEvent, GtidEvent, StopEvent,
     BeginLoadQueryEvent, ExecuteLoadQueryEvent,
     HeartbeatLogEvent, NotImplementedEvent)
+from .exceptions import BinLogNotEnabled
 from .row_event import (
     UpdateRowsEvent, WriteRowsEvent, DeleteRowsEvent, TableMapEvent)
 
@@ -305,7 +306,10 @@ def __connect_to_stream(self):
             if self.log_file is None or self.log_pos is None:
                 cur = self._stream_connection.cursor()
                 cur.execute("SHOW MASTER STATUS")
-                self.log_file, self.log_pos = cur.fetchone()[:2]
+                master_status = cur.fetchone()
+                if master_status is None:
+                    raise BinLogNotEnabled()
+                self.log_file, self.log_pos = master_status[:2]
                 cur.close()
 
             prelude = struct.pack('<i', len(self.log_file) + 11) \

pymysqlreplication/exceptions.py

@@ -1,3 +1,8 @@
 class TableMetadataUnavailableError(Exception):
     def __init__(self, table):
         Exception.__init__(self,"Unable to find metadata for table {0}".format(table))
+
+
+class BinLogNotEnabled(Exception):
+    def __init__(self):
+        Exception.__init__(self, "MySQL binary loggging is not enabled.")