Fix roll_dep.py to print the right latest SVN revision number on error.

roll_dep.py

 #!/usr/bin/env python
 # Copyright (c) 2014 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.
 
 """This scripts takes the path to a dep and an svn revision, and updates the
 parent repo's DEPS file with the corresponding git revision.  Sample invocation:
 
 [chromium/src]$ roll-dep third_party/WebKit 12345
 
@@ skipping 89 matching lines @@
     m = GIT_SVN_ID_RE.match(line.strip())
     if m:
       return m.group(1)
   return None
 
 
 def convert_svn_revision(dep_path, revision):
   """Find the git revision corresponding to an svn revision."""
   err_msg = 'Unknown error'
   revision = int(revision)
+  latest_svn_rev = None
   with open(os.devnull, 'w') as devnull:
     for ref in ('HEAD', 'origin/master'):
       try:
         log_p = Popen(['git', 'log', ref],
                       cwd=dep_path, stdout=PIPE, stderr=devnull)
         grep_p = Popen(['grep', '-e', '^commit ', '-e', '^ *git-svn-id: '],
                        stdin=log_p.stdout, stdout=PIPE, stderr=devnull)
         git_rev = None
         prev_svn_rev = None
         for line in grep_p.stdout:
           if line.startswith('commit '):
             git_rev = line.split()[1]
             continue
           try:
             svn_rev = int(line.split()[1].partition('@')[2])
           except (IndexError, ValueError):
             print >> sys.stderr, (
                 'WARNING: Could not parse svn revision out of "%s"' % line)
             continue
+          if not latest_svn_rev or int(svn_rev) > int(latest_svn_rev):
+            latest_svn_rev = svn_rev
           if svn_rev == revision:
             return git_rev
           if svn_rev > revision:
             prev_svn_rev = svn_rev
             continue
           if prev_svn_rev:
             err_msg = 'git history skips from revision %d to revision %d.' % (
                 svn_rev, prev_svn_rev)
           else:
             err_msg = (
                 'latest available revision is %d; you may need to '
-                '"git fetch origin" to get the latest commits.' % svn_rev)
+                '"git fetch origin" to get the latest commits.' %
+                latest_svn_rev)
       finally:
         log_p.terminate()
         grep_p.terminate()
   raise RuntimeError('No match for revision %d; %s' % (revision, err_msg))
 
 
 def get_git_revision(dep_path, revision):
   """Convert the revision argument passed to the script to a git revision."""
   svn_revision = None
   if revision.startswith('r'):
@@ skipping 196 matching lines @@
   soln = get_solution(gclient_root, dep_path)
   soln_path = os.path.relpath(os.path.join(gclient_root, soln['name']))
   dep_name = posix_path(os.path.relpath(dep_path, gclient_root))
   (git_rev, svn_rev) = get_git_revision(dep_path, revision)
   comment = ('from svn revision %s' % svn_rev) if svn_rev else None
   assert git_rev, 'Could not find git revision matching %s.' % revision
   return update_deps(soln_path, dep_path, dep_name, git_rev, comment)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))