Track the status of the gerritChangeSource process

separately from self.parent, which does not mean 'running'

Fixes #2208.

master/buildbot/changes/gerritchangesource.py

@@ -62,6 +62,7 @@ def __init__(self, gerritserver, username, gerritport=29418, identity_file=None)
         self.username = username
         self.identity_file = identity_file
         self.process = None
+        self.wantProcess = False
         self.streamProcessTimeout = self.STREAM_BACKOFF_MIN
 
     class LocalPP(ProcessProtocol):
@@ -151,8 +152,8 @@ def eventReceived_ref_updated(self, properties, event):
     def streamProcessStopped(self):
         self.process = None
 
-        # if the service is stopped, don't try to restart
-        if not self.parent:
+        # if the service is stopped, don't try to restart the process
+        if not self.wantProcess:
             log.msg("service is not running; not reconnecting")
             return
 
@@ -181,9 +182,11 @@ def startStreamProcess(self):
           [ "ssh" ] + args + [ "gerrit", "stream-events" ])
 
     def startService(self):
+        self.wantProcess = True
         self.startStreamProcess()
 
     def stopService(self):
+        self.wantProcess = False
         if self.process:
             self.process.signalProcess("KILL")
         # TODO: if this occurs while the process is restarting, some exceptions may