Set remote URL after config was updated

To avoid issues with outdated Github access tokens in the Git config we
only update the remote URL on the repo object after the config update
was successful.

This also adds a missing repo lock when building the repo state.

Change-Id: I8e1b5b26f03cb75727d2b2e3c9310214a3eac447

zuul/merger/merger.py

@@ -733,10 +733,8 @@ class Repo(object):
             return
         log = get_annotated_logger(self.log, zuul_event_id)
         log.debug("Set remote url to %s", redact_url(url))
+        self._git_set_remote_url(self.createRepoObject(zuul_event_id), url)
         self.remote_url = url
-        self._git_set_remote_url(
-            self.createRepoObject(zuul_event_id),
-            self.remote_url)
 
     def mapLine(self, commit, filename, lineno, zuul_event_id=None):
         repo = self.createRepoObject(zuul_event_id)
@@ -1244,11 +1242,13 @@ class Merger(object):
                         item['connection'], item['project'], repo_state,
                         item['ref'], item['newrev'])
         item = items[-1]
-        repo = self.getRepo(item['connection'], item['project'])
         # A list of branch names the last item appears in.
         item_in_branches = []
         if item.get('newrev'):
-            item_in_branches = repo.contains(item['newrev'])
+            lock = repo_locks.getRepoLock(item['connection'], item['project'])
+            with lock:
+                repo = self.getRepo(item['connection'], item['project'])
+                item_in_branches = repo.contains(item['newrev'])
         return (True, repo_state, item_in_branches)
 
     def getFiles(self, connection_name, project_name, branch, files, dirs=[]):