git cl for Gerrit: make --squash generate Change-Id directly.

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index c5efc980bb6e1d98555c0c75f9133363774146d8..c4a8227b828c5043460b674dd3d57816bcf58c06 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -64,7 +64,6 @@ DEFAULT_SERVER = 'https://codereview.appspot.com'
 POSTUPSTREAM_HOOK_PATTERN = '.git/hooks/post-cl-%s'
 DESCRIPTION_BACKUP_FILE = '~/.git_cl_description_backup'
 GIT_INSTRUCTIONS_URL = 'http://code.google.com/p/chromium/wiki/UsingGit'
-CHANGE_ID = 'Change-Id:'
 REFS_THAT_ALIAS_TO_OTHER_REFS = {
     'refs/remotes/origin/lkgr': 'refs/remotes/origin/master',
     'refs/remotes/origin/lkcr': 'refs/remotes/origin/master',
@@ -2209,40 +2208,17 @@ def GerritUpload(options, args, cl, change):
     if not message:
       if not options.force:
         change_desc.prompt()
-
-      if CHANGE_ID not in change_desc.description:
-        # Run the commit-msg hook without modifying the head commit by writing
-        # the commit message to a temporary file and running the hook over it,
-        # then reading the file back in.
-        commit_msg_hook = os.path.join(settings.GetRoot(), '.git', 'hooks',
-                                       'commit-msg')
-        file_handle, msg_file = tempfile.mkstemp(text=True,
-                                                 prefix='commit_msg')
-        logging.debug("%s %s", file_handle, msg_file)
-        try:
-          try:
-            try:
-              fileobj = os.fdopen(file_handle, 'w')
-            except OSError:
-              # if fdopen fails, file_handle remains open.
-              # See https://docs.python.org/2/library/os.html#os.fdopen.
-              os.close(file_handle)
-              raise
-            with fileobj:
-              # This will close the file_handle.
-              fileobj.write(change_desc.description)
-            logging.debug("%s %s finish editing", file_handle, msg_file)
-          finally:
-            RunCommand([commit_msg_hook, msg_file])
-            change_desc.set_description(gclient_utils.FileRead(msg_file))
-        finally:
-          os.remove(msg_file)
-
       if not change_desc.description:
         print "Description is empty; aborting."
         return 1
-
       message = change_desc.description
+      change_ids = git_footers.get_footer_change_id(message)
+      if len(change_ids) > 1:
+        DieWithError('too many Change-Id footers in %s branch' % shadow_branch)

[Bons, 2016/03/03 03:19:52]

is there any way to give the user more info as to what they can do to rectify
the situation?

[tandrii(chromium), 2016/03/04 11:55:23]

no, because the message came from the shadow branch, that the user isn't even
supposed to touch. I'm getting rid of it in future CL, and this message will
also get somewhat refactored.

+      if not change_ids:
+        message = git_footers.add_footer_change_id(
+            message, GenerateGerritChangeId(message))
+        change_desc.set_description(message)
 
     remote, upstream_branch = cl.FetchUpstreamTuple(cl.GetBranch())
     if remote is '.':