Explicitely tell to git we are interested about log from different branch, not...

Explicitely tell to git we are interested about log from different branch, not for possibly same named file (issue #70)

weblate/trans/models.py

@@ -659,7 +659,7 @@ class SubProject(models.Model):
         '''
         if gitrepo is None:
             gitrepo = self.get_repo()
-        status = gitrepo.git.log(revision)
+        status = gitrepo.git.log(revision, '--')
         if status == '':
             # No changes to merge
             return False