depot_tools: Add git svn find-rev for safesync_url parsing (commonly LKGR link).

gclient_scm.py

Index: gclient_scm.py
===================================================================
--- gclient_scm.py	(revision 109214)
+++ gclient_scm.py	(working copy)
@@ -476,6 +476,35 @@
       files = self._Capture(['diff', '--name-only', merge_base]).split()
       file_list.extend([os.path.join(self.checkout_path, f) for f in files])
 
+  @staticmethod
+  def GetUsableRev(cwd, url, rev, options):
+    """Finds a useful revision for this repository.
+    
+    If SCM is git-svn and the head revision is less than |rev|, git svn fetch
+    will be called on the source."""
+    sha1 = None
+    # As an optimization, only verify an SVN revision as [0-9]{1,6} for now to
+    # avoid making a network request.
+    if (scm.GIT.IsGitSvn(cwd=cwd) and
+        rev.isdigit() and len(rev) < 7):
+      local_head = scm.GIT.GetGitSvnHeadRev(cwd=cwd)
+      if not local_head or local_head < int(rev):
+        if options.verbose:
+          print('Running git svn fetch. This might take a while.\n')
+        scm.GIT.Capture(['svn', 'fetch'], cwd=cwd)
+      sha1 = scm.GIT.GetSha1ForSvnRev(cwd=cwd, rev=rev)
+    else:
+      sha1 = scm.GIT.IsValidRevision(cwd=cwd, url=url, rev=rev)
+    if sha1:
+      return sha1
+    else:
+      help_url = ''.join(['http://code.google.com/p/chromium/wiki/UsingNewGit',

[M-A Ruel, 2011/11/09 14:16:08]

Replace lines 498-506 with:

    if not sha1:
      raise gclient_utils.Error(
          ( '%s is not a value hash. Safesync URLs with a git checkout\n'
            'currently require a git-svn remote or a safesync_url that\n'
            'provides git sha1s. Please add a git-svn remote or change\n'
            'your safesync_url. For more info, see:\n'
            'http://code.google.com/p/chromium/wiki/UsingNewGit'
            '#Initial_checkout') % rev)
    return sha1

[Dan Beam, 2011/11/10 10:29:15]

Done.

+                          '#Initial_checkout'])
+      raise gclient_utils.Error(
+          'Safesync URLs with a git checkout currently require a git-svn '
+          'remote or a safesync_url that provides git sha1s. Please add a '
+          'git-svn remote or change your safesync_url. %s' % help_url)
+
   def FullUrlForRelativeUrl(self, url):
     # Strip from last '/'
     # Equivalent to unix basename
@@ -991,6 +1020,15 @@
     else:
       self._RunAndGetFileList(command, options, file_list)
 
+  @staticmethod
+  def GetUsableRev(cwd, url, rev, options):
+    """Finds a useful revision for this repository."""

[M-A Ruel, 2011/11/09 14:16:08]

Verifies the validity of the revision for this repository.

[Dan Beam, 2011/11/10 10:29:15]

Done.

+    if scm.SVN.IsValidRevision(cwd=cwd, url=url, rev=rev):

[M-A Ruel, 2011/11/09 14:16:08]

I think you should do the url@revision formatting here instead of inside
IsValidRevision().

[Dan Beam, 2011/11/09 19:21:59]

I guess I could, but the git version doesn't use this so that's why I'm just
passing cwd, url, and rev to keep the API between each version uniform.  SVN
does svn info url@rev, git uses git parse-rev rev in the cwd.

[Dan Beam, 2011/11/10 10:29:15]

Done.

+      return rev
+    raise gclient_utils.Error(
+        'The content of safesync_url doesn\'t look like a valid Subversion '

[M-A Ruel, 2011/11/09 14:16:08]

Prepend '%s isn't a valid revision'

[Dan Beam, 2011/11/10 10:29:15]

Done.

+        'revision. Please check that your safesync_url is correct.')
+
   def FullUrlForRelativeUrl(self, url):
     # Find the forth '/' and strip from there. A bit hackish.
     return '/'.join(self.url.split('/')[:4]) + url