subrepo: svn abort now depends on exit code (issue2833)

mercurial/subrepo.py

@@ -543,8 +543,10 b' class svnsubrepo(abstractsubrepo):'
                              universal_newlines=True, env=env)
         stdout, stderr = p.communicate()
         stderr = stderr.strip()
+        if p.returncode:
+            raise util.Abort(stderr or 'exited with code %d' % p.returncode)
         if stderr:
-            raise util.Abort(stderr)
+            self._ui.warn(stderr + '\n')
         return stdout
 
     @propertycache