[release] Let release script fix missing tags.

Check if a previous run left an inconsistent state behind.
The check is right before trying to push a new state as then
all information is available, like commit message and tag
name.

This is still only a band-aid. If gnumbd is down for a
longer period, an unprocessed commit won't be found, but
the push attempt will still fail.

Review URL: https://codereview.chromium.org/1887583002

Cr-Commit-Position: refs/heads/master@{#35437}

tools/release/create_release.py

@@ -223,6 +223,27 @@ class CommitBranch(Step):
     os.remove(self.Config("CHANGELOG_ENTRY_FILE"))
 
 
+class FixBrokenTag(Step):
+  MESSAGE = "Check for a missing tag and fix that instead."
+
+  def RunStep(self):
+    commit = None
+    try:
+      commit = self.GitLog(
+          n=1, format="%H",
+          grep=self["commit_title"],
+          branch="origin/%s" % self["version"],
+      )
+    except GitFailedException:
+      # In the normal case, the remote doesn't exist yet and git will fail.
+      pass
+    if commit:
+      print "Found %s. Trying to repair tag and bail out." % self["version"]
+      self.step.Git("tag %s %s" % (self["version"], commit))
+      self.step.Git("push origin %s" % self["version"])
+      return True
+
+
 class PushBranch(Step):
   MESSAGE = "Push changes."
 
@@ -303,6 +324,7 @@ class CreateRelease(ScriptsBase):
       SetVersion,
       EnableMergeWatchlist,
       CommitBranch,
+      FixBrokenTag,
       PushBranch,
       TagRevision,
       CleanUp,

tools/release/test_scripts.py

@@ -970,6 +970,8 @@ Performance and stability improvements on all platforms."""
           cb=self.WriteFakeWatchlistsFile),
       Cmd("git commit -aF \"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], "",
           cb=CheckVersionCommit),
+      Cmd("git log -1 --format=%H --grep=\"Version 3.22.5\" origin/3.22.5",
+          ""),
       Cmd("git push origin "
           "refs/heads/work-branch:refs/pending/heads/3.22.5 "
           "push_hash:refs/pending-tags/heads/3.22.5 "