Fix webkit build failure reported by evan@

build/util/lastchange.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """
 lastchange.py -- Chromium revision fetching utility.
 """
 
 import re
@@ skipping 112 matching lines @@
 def FetchGitSVNURL(directory):
   """
   Fetch URL of SVN repository bound to git.
 
   Errors are swallowed.
 
   Returns:
     SVN URL.
   """
   if not IsGitSVN(directory):
-    return None
+    return ''
   proc = RunGitCommand(directory, ['svn', 'info', '--url'])
   if proc:
     output = proc.communicate()[0].strip()
     if proc.returncode == 0:
-      return output
-  return None
+      match = re.search('^.*://.*$', output, re.M)

[Evan Martin, 2011/03/03 19:49:31]

Maybe use
  r'^\w+://.*$'
just to make it harder to accidentally match.  (What you have searches for any
line that has a "://" in it...)

[Denis Lagno, 2011/03/03 20:18:39]

Done.

should I use those 'raw string literals'?  I do not observe
any difference during execution.

+      if match:
+        return match.group(0)
+  return ''
+
+
+def FetchGitSVNRoot(directory):
+  """
+  Fetch root of SVN repository bound to git.

[Evan Martin, 2011/03/03 19:49:31]

This part of the change seems unrelated to the bug (?)

[Denis Lagno, 2011/03/03 20:18:39]

yes.  But only now I realized how URL and Root are used.
Normally root is expected to be a prefix of URL.
Should I send it as a separate patch?  

+
+  Errors are swallowed.
+
+  Returns:
+    SVN root repository.
+  """
+  if not IsGitSVN(directory):
+    return ''
+  git_command = ['config', '--get-regexp', '^svn-remote.svn.url$']
+  proc = RunGitCommand(directory, git_command)
+  if proc:
+    output = proc.communicate()[0].strip()
+    if proc.returncode == 0:
+      match = re.search('\S*$', output)
+      if match:
+        return match.group(0)
+  return ''
 
 
 def LookupGitSVNRevision(directory, depth):
   """
   Fetch the Git-SVN identifier for the local tree.
   Parses first |depth| commit messages.
 
   Errors are swallowed.
   """
   if not IsGitSVN(directory):
     return None
-  git_re = re.compile('^\s*git-svn-id:\s+(\S+)@(\d+)', re.M)
+  git_re = re.compile('^\s*git-svn-id:\s+(\S+)@(\d+)')
   proc = RunGitCommand(directory, ['log', '-' + str(depth)])
   if proc:
     for line in proc.stdout:
       match = git_re.search(line)
       if match:
         id = match.group(2)
         if id:
           proc.stdout.close()  # Cut pipe for fast exit.
           return id
   return None
@@ skipping 15 matching lines @@
   Fetch the Git-SVN identifier for the local tree.
 
   Errors are swallowed.
   """
   # We assume that at least first 999 commit messages contain svn evidence.
   revision = LookupGitSVNRevision(directory, 999)
   if not revision:
     return None
   if IsGitSVNDirty(directory):
     revision = revision + '-dirty'
-  return VersionInfo(FetchGitSVNURL(directory), 'git-svn', revision)
+  url = FetchGitSVNURL(directory)
+  root = FetchGitSVNRoot(directory)
+  return VersionInfo(url, root, revision)
 
 
 def FetchVersionInfo(default_lastchange, directory=None):
   """
   Returns the last change (in the form of a branch, revision tuple),
   from some appropriate revision control system.
   """
   version_info = (FetchSVNRevision(directory) or
       FetchGitSVNRevision(directory) or FetchGitRevision(directory))
   if not version_info:
@@ skipping 53 matching lines @@
     if out_file:
       WriteIfChanged(out_file, contents)
     else:
       sys.stdout.write(contents)
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())