Use reset --soft to squash before dcomitting.

git_cl/git_cl.py

 #!/usr/bin/python
 # git-cl -- a git-command for integrating reviews on Rietveld
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 import errno
 import logging
 import optparse
 import os
 import re
 import subprocess
@@ skipping 940 matching lines @@
   print 'Description:', repr(description)
 
   branches = [base_branch, cl.GetBranchRef()]
   if not options.force:
     subprocess.call(['git', 'diff', '--stat'] + branches)
     raw_input("About to commit; enter to confirm.")
 
   # We want to squash all this branch's commits into one commit with the
   # proper description.
   # We do this by doing a "merge --squash" into a new commit branch, then
   # dcommitting that.

[evanm, 2011/02/25 18:13:15]

This comment needs to be updated.

[Bernhard Bauer, 2011/02/27 15:03:16]

Done.

   MERGE_BRANCH = 'git-cl-commit'
   # Delete the merge branch if it already exists.
   if RunGitWithCode(['show-ref', '--quiet', '--verify',
                      'refs/heads/' + MERGE_BRANCH])[0] == 0:
     RunGit(['branch', '-D', MERGE_BRANCH])
 
   # We might be in a directory that's present in this branch but not in the
   # trunk.  Move up to the top of the tree so that git commands that expect a
   # valid CWD won't fail after we check out the merge branch.
   rel_base_path = RunGit(['rev-parse', '--show-cdup']).strip()
   if rel_base_path:
     os.chdir(rel_base_path)
 
   # Stuff our change into the merge branch.
   # We wrap in a try...finally block so if anything goes wrong,
   # we clean up the branches.
   retcode = -1
   try:
-    RunGit(['checkout', '-q', '-b', MERGE_BRANCH, base_branch])
-    RunGit(['merge', '--squash', cl.GetBranchRef()])
+    RunGit(['checkout', '-q', '-b', MERGE_BRANCH])
+    RunGit(['reset', '--soft', base_branch])
     if options.contributor:
       RunGit(['commit', '--author', options.contributor, '-m', description])
     else:
       RunGit(['commit', '-m', description])
     if cmd == 'push':
       # push the merge branch.
       remote, branch = cl.FetchUpstreamTuple()
       retcode, output = RunGitWithCode(
           ['push', '--porcelain', remote, 'HEAD:%s' % branch])
       logging.debug(output)
@@ skipping 277 matching lines @@
             ('AppEngine is misbehaving and returned HTTP %d, again. Keep faith '
              '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__':
   sys.exit(main(sys.argv[1:]))