git cl: save description before doing any RPCs during upload.

R=smut@google.com

Bug: 881860
Change-Id: I59c337384891f02dbd2cc776318803ac556843ca
Reviewed-on: https://chromium-review.googlesource.com/1247584Reviewed-by: smut <smut@google.com>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

git_cl.py

@@ -107,8 +107,7 @@ def DieWithError(message, change_desc=None):
 
 def SaveDescriptionBackup(change_desc):
   backup_path = os.path.expanduser(DESCRIPTION_BACKUP_FILE)
-  print('\nError after CL description prompt -- saving description to %s\n' %
-        backup_path)
+  print('\nsaving CL description to %s\n' % backup_path)
   backup_file = open(backup_path, 'w')
   backup_file.write(change_desc.description)
   backup_file.close()
@@ -3014,6 +3013,7 @@ class _GerritChangelistImpl(_ChangelistCodereviewBase):
       change_id = git_footers.get_footer_change_id(change_desc.description)[0]
 
     assert change_desc
+    SaveDescriptionBackup(change_desc)
     commits = RunGitSilent(['rev-list', '%s..%s' % (parent,
                                                     ref_to_push)]).splitlines()
     if len(commits) > 1:

tests/git_cl_test.py

@@ -661,6 +661,8 @@ class TestGitCl(TestCase):
                   self._mocked_call(['get_or_create_merge_base']+list(a))))
     self.mock(git_cl, 'BranchExists', lambda _: True)
     self.mock(git_cl, 'FindCodereviewSettingsFile', lambda: '')
+    self.mock(git_cl, 'SaveDescriptionBackup', lambda _:
+              self._mocked_call('SaveDescriptionBackup'))
     self.mock(git_cl, 'ask_for_data', lambda *a, **k: self._mocked_call(
               *(['ask_for_data'] + list(a)), **k))
     self.mock(git_cl, 'write_json', lambda path, contents:
@@ -1240,6 +1242,7 @@ class TestGitCl(TestCase):
       ref_to_push = 'HEAD'
 
     calls += [
+      (('SaveDescriptionBackup',), None),
       ((['git', 'rev-list',
          (custom_cl_base if custom_cl_base else expected_upstream_ref) + '..' +
          ref_to_push],),