'git cl issue 0': Remove Change-Id

Although git-cl-upload warns when uploading a new patchset
to a change owned by someone else, if the uploader has run
'git cl issue 0', then git-cl believes they'll be uploading
a new change, so it doesn't bother checking. However, once
the upload begins, Gerrit notices the Change-Id in the commit
message, and instead adds a new patchset to someone else's
review (if the uploader is a committer).

This change introduces some logic to git-cl-issue to also
remove any Change-Id from the commit message when a user
tries to clear the metadata about their branch.

Bug: 741648
Change-Id: I6c7c3b24a7fc09c68220c8200b732fbdf9cf1fd3
Reviewed-on: https://chromium-review.googlesource.com/568267Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Aaron Gable <agable@chromium.org>

git_cl.py

@@ -1471,6 +1471,12 @@ class Changelist(object):
             self._codereview_impl.CodereviewServerConfigKey(),
             codereview_server)
     else:
+      desc = self.GetDescription()
+      if git_footers.get_footer_change_id(desc):
+        print('WARNING: The change patched into this branch has a Change-Id. '
+              'Removing it.')
+        RunGit(['commit', '--amend', '-m',
+                git_footers.remove_footer(desc, 'Change-Id')])
       # Reset all of these just to be clean.
       reset_suffixes = [
           'last-upload-hash',

tests/git_cl_test.py

@@ -2647,10 +2647,33 @@ class TestGitCl(TestCase):
   def test_cmd_issue_erase_existing(self):
     out = StringIO.StringIO()
     self.mock(git_cl.sys, 'stdout', out)
+    self.mock(git_cl.Changelist, 'GetDescription',
+              lambda _: 'This is a description')
+    self.calls = [
+        ((['git', 'symbolic-ref', 'HEAD'],), 'feature'),
+        ((['git', 'config', 'branch.feature.rietveldissue'],), CERR1),
+        ((['git', 'config', 'branch.feature.gerritissue'],), '123'),
+        # Let this command raise exception (retcode=1) - it should be ignored.
+        ((['git', 'config', '--unset', 'branch.feature.last-upload-hash'],),
+         CERR1),
+        ((['git', 'config', '--unset', 'branch.feature.gerritissue'],), ''),
+        ((['git', 'config', '--unset', 'branch.feature.gerritpatchset'],), ''),
+        ((['git', 'config', '--unset', 'branch.feature.gerritserver'],), ''),
+        ((['git', 'config', '--unset', 'branch.feature.gerritsquashhash'],),
+         ''),
+    ]
+    self.assertEqual(0, git_cl.main(['issue', '0']))
+
+  def test_cmd_issue_erase_existing_with_change_id(self):
+    out = StringIO.StringIO()
+    self.mock(git_cl.sys, 'stdout', out)
+    self.mock(git_cl.Changelist, 'GetDescription',
+              lambda _: 'This is a description\n\nChange-Id: Ideadbeef')
     self.calls = [
         ((['git', 'symbolic-ref', 'HEAD'],), 'feature'),
         ((['git', 'config', 'branch.feature.rietveldissue'],), CERR1),
         ((['git', 'config', 'branch.feature.gerritissue'],), '123'),
+        ((['git', 'commit', '--amend', '-m', 'This is a description\n'],), ''),
         # Let this command raise exception (retcode=1) - it should be ignored.
         ((['git', 'config', '--unset', 'branch.feature.last-upload-hash'],),
          CERR1),