gclient: in managed mode, warn if .gclient has a mismatched URL

gclient.py

Index: gclient.py
diff --git a/gclient.py b/gclient.py
index 86b742f594ed7252674207cd286ecd5f06fca115..86fb026ce93e6baa2d97d6c76b4ff674ee250417 100755
--- a/gclient.py
+++ b/gclient.py
@@ -1220,6 +1220,25 @@ solutions = [
     """
     if not self.dependencies:
       raise gclient_utils.Error('No solution specified')
+
+    for dep in self.dependencies:
+      if dep.managed:
+        scm = gclient_scm.CreateSCM(dep.url, self.root_dir, dep.name)
+        if not scm.DoesRemoteURLMatch():
+          actual_url = scm.GetActualRemoteURL()
+          raise gclient_utils.Error('''
+Your .gclient file seems to be broken. The requested URL is different from what
+is actually checked out in %s:
+
+Expected: %s
+Actual:   %s

[iannucci, 2014/03/13 18:27:27]

I would also list the SCM which we would have selected in either case.

[borenet, 2014/03/13 18:57:25]

Done.

+
+If you're managing your own git checkout in %s but the URL in .gclient is for
+an svn repository, you probably want to set 'managed': False in .gclient.

[iannucci, 2014/03/13 18:27:27]

do we also want to advise that they correct the url to be git?

[borenet, 2014/03/13 18:57:25]

Sure, but the URL doesn't matter in unmanaged mode.

+Otherwise, you should ensure that the URL listed in .gclient is correct and
+either change it or fix the checkout.
+'''  % (os.path.join(self.root_dir, dep.name), dep.url, actual_url, dep.name))
+
     revision_overrides = {}
     # It's unnecessary to check for revision overrides for 'recurse'.
     # Save a few seconds by not calling _EnforceRevisions() in that case.
@@ -1694,6 +1713,7 @@ def CMDsync(parser, args):
     # Print out the .gclient file.  This is longer than if we just printed the
     # client dict, but more legible, and it might contain helpful comments.
     print(client.config_content)
+
   ret = client.RunOnDeps('update', args)
   if options.output_json:
     slns = {}