Fix safesync_url handling for git.

Takes into account the new submodule-enabled repository layout.
Review URL: https://codereview.chromium.org/11098064

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@161403 0039d316-1c4b-4281-b951-d872f2087c98

gclient_scm.py

@@ -589,7 +589,14 @@ class GitWrapper(SCMWrapper):
           if options.verbose:
             print('Running git svn fetch. This might take a while.\n')
           scm.GIT.Capture(['svn', 'fetch'], cwd=self.checkout_path)
+        try:
           sha1 = scm.GIT.GetSha1ForSvnRev(cwd=self.checkout_path, rev=rev)
+        except gclient_utils.Error, e:
+          sha1 = e.message
+          print('\nWarning: Could not find a git revision with accurate\n'
+                 '.DEPS.git that maps to SVN revision %s.  Sync-ing to\n'
+                 'the closest sane git revision, which is:\n'
+                 '  %s\n' % (rev, e.message))
         if not sha1:
           raise gclient_utils.Error(
               ( 'It appears that either your git-svn remote is incorrectly\n'

scm.py

@@ -402,8 +402,23 @@ class GIT(object):
     if not GIT.IsGitSvn(cwd=cwd):
       return None
     try:
-      output = GIT.Capture(['svn', 'find-rev', 'r' + str(rev)], cwd=cwd)
-      return GIT.ParseGitSvnSha1(output)
+      git_svn_rev = GIT.Capture(
+          ['svn', 'find-rev', 'r' + str(rev)], cwd=cwd).rstrip()
+      if not git_svn_rev:
+        return None
+      output = GIT.Capture(
+          ['rev-list', '--ancestry-path', '--reverse',
+          '--grep', 'SVN changes up to revision [0-9]*',
+          '%s..refs/remotes/origin/master' % git_svn_rev], cwd=cwd)
+      if not output:
+        return None
+      sha1 = output.splitlines()[0]
+      if not sha1:
+        return None
+      output = GIT.Capture(['rev-list', '-n', '1', '%s^1' % sha1], cwd=cwd)
+      if git_svn_rev != output.rstrip():
+        raise gclient_utils.Error(sha1)
+      return sha1
     except subprocess2.CalledProcessError:
       return None