git_cl sanity checks

git_cl.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld."""
 
 import json
@@ skipping 145 matching lines @@
   dirty = RunGit(['diff-index', '--name-status', 'HEAD'])
   if dirty:
     print 'Cannot %s with a dirty tree. You must commit locally first.' % cmd
     print 'Uncommitted files: (git diff-index --name-status HEAD)'
     print dirty[:4096]
     if len(dirty) > 4096:
       print '... (run "git diff-index --name-status HEAD" to see full output).'
     return True
   return False
 
+
+def git_cl_sanity_checks(upstream_git_obj):
+  # First verify that the commit we're diffing against is in our tree.
+  upstream_sha = RunGit(['rev-parse', '--verify', upstream_git_obj]).strip()
+  common_ancestor = RunGit(['merge-base', upstream_sha, 'HEAD']).strip()
+  if upstream_sha != common_ancestor:

[M-A Ruel, 2012/10/27 01:29:41]

I disagree with this check. It happens I git fetch but do not rebase, simply
because I rebased for one of the CL I'm working on but not another one.

[Isaac (away), 2012/10/27 01:32:55]

This is intended to catch diffing against a rebased branch while your current
branch is not rebased.  That means the diff will pull in diff from lots of other
commits.

I'm not clear why your scenario would trigger this -- can you clarify?

[M-A Ruel, 2012/10/27 01:37:23]

git checkout -b work origin/master
vim foo
git commit -a -m "Rock on"
git checkout -b leisure origin/master
git pull
# Assumes something was pulled.
git checkout work
git cl upload
# Note upstream == origin/master, but "ref-parse origin/master" != "merge-base
origin/master HEAD"

+    print >> sys.stderr, (
+        'ERROR: %s is not in the current branch.  You may need to rebase your '
+        'tracking branch' % upstream_sha)
+    return False
+
+  commits_in_diff = RunGit(
+      ['rev-list', '^%s' % upstream_sha, 'HEAD']).splitlines()
+  commits_in_origin = RunGit(
+      ['rev-list', '^%s' % upstream_sha, 'remotes/origin/master']).splitlines()
+
+  common_commits = set(commits_in_diff) & set(commits_in_origin)
+  if common_commits:
+    print >> sys.stderr, (
+        'ERROR: Your diff contains %d commits already in origin/master.\n'
+        'Run "git log --oneline origin/master..HEAD" to get a list of commits '
+        'in the diff' % len(common_commits))
+    return False
+  return True
+
+
 def MatchSvnGlob(url, base_url, glob_spec, allow_wildcards):
   """Return the corresponding git ref if |base_url| together with |glob_spec|
   matches the full |url|.
 
   If |allow_wildcards| is true, |glob_spec| can contain wildcards (see below).
   """
   fetch_suburl, as_ref = glob_spec.split(':')
   if allow_wildcards:
     glob_match = re.match('(.+/)?(\*|{[^/]*})(/.+)?', fetch_suburl)
     if glob_match:
@@ skipping 424 matching lines @@
     if issue:
       RunGit(['config', self._IssueSetting(), str(issue)])
       if self.rietveld_server:
         RunGit(['config', self._RietveldServer(), self.rietveld_server])
     else:
       RunGit(['config', '--unset', self._IssueSetting()])
       self.SetPatchset(0)
     self.has_issue = False
 
   def GetChange(self, upstream_branch, author):
+    if not git_cl_sanity_checks(upstream_branch):
+      DieWithError('\nGit sanity check failure')
+
     root = RunCommand(['git', 'rev-parse', '--show-cdup']).strip() or '.'
     absroot = os.path.abspath(root)
 
     # We use the sha1 of HEAD as a name of this change.
     name = RunCommand(['git', 'rev-parse', 'HEAD']).strip()
     # Need to pass a relative path for msysgit.
     try:
       files = scm.GIT.CaptureStatus([root], '.', upstream_branch)
     except subprocess2.CalledProcessError:
       DieWithError(
@@ skipping 1189 matching lines @@
              'and retry or visit go/isgaeup.\n%s') % (e.code, str(e)))
 
   # Not a known command. Default to help.
   GenUsage(parser, 'help')
   return CMDhelp(parser, argv)
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   sys.exit(main(sys.argv[1:]))