Add support to check if the url has changed for a git dep and create a new clone.

gclient_scm.py

 # Copyright (c) 2010 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 168 matching lines @@
     rev_str = ' at %s' % revision
     files = []
 
     printed_path = False
     verbose = []
     if options.verbose:
       print('\n_____ %s%s' % (self.relpath, rev_str))
       verbose = ['--verbose']
       printed_path = True
 
+    current_url = self._Capture(['config', 'remote.origin.url'])
+    if current_url != url:
+      print('_____ switching %s to a new checkout' % self.relpath)

[M-A Ruel, 2011/03/24 14:49:42]

to a new upstream

+      self._CheckClean(rev_str)

[TVL, 2011/03/24 14:43:19]

actually, this doesn't seem to catch new files.  do we have anything to catch
that?

+      gclient_utils.RemoveDirectory(self.checkout_path)

[M-A Ruel, 2011/03/24 14:49:42]

You don't need to remove the directory at all. Something like that would make
sense:
git remote set-url origin <newurl>
git fetch origin --prune --quiet
# Then forcibly rebase master on the new origin, that needs to be tested.
git reset --hard origin/master

+
     if revision.startswith('refs/heads/'):
       rev_type = "branch"
     elif revision.startswith('origin/'):
       # For compatability with old naming, translate 'origin' to 'refs/heads'
       revision = revision.replace('origin/', 'refs/heads/')
       rev_type = "branch"
     else:
       # hash is also a tag, only make a distinction at checkout
       rev_type = "hash"
 
@@ skipping 705 matching lines @@
 
     This method returns a new list to be used as a command."""
     new_command = command[:]
     if revision:
       new_command.extend(['--revision', str(revision).strip()])
     # --force was added to 'svn update' in svn 1.5.
     if ((options.force or options.manually_grab_svn_rev) and
         scm.SVN.AssertVersion("1.5")[0]):
       new_command.append('--force')
     return new_command