upload: add a --topic option for setting topic explicitly

Let people specify the exact topic when uploading CLs.  The existing
-t option only supports setting the topic to the current local branch.

Add a --topic-branch long option to the existing -t to align it a bit
better with --hashtag & --hashtag-branch.

Change-Id: I010abc4a7f3c685021cae776dd1e597c22b79135
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/431997
Tested-by: Mike Frysinger <vapier@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Mike Frysinger <vapier@google.com>

subcmds/upload.py

@@ -218,9 +218,14 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
     def _Options(self, p):
         p.add_option(
             "-t",
+            "--topic-branch",
             dest="auto_topic",
             action="store_true",
-            help="send local branch name to Gerrit Code Review",
+            help="set the topic to the local branch name",
+        )
+        p.add_option(
+            "--topic",
+            help="set topic for the change",
         )
         p.add_option(
             "--hashtag",
@@ -551,9 +556,12 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
 
         # Check if topic branches should be sent to the server during
         # upload.
-        if opt.auto_topic is not True:
-            key = "review.%s.uploadtopic" % branch.project.remote.review
-            opt.auto_topic = branch.project.config.GetBoolean(key)
+        if opt.topic is None:
+            if opt.auto_topic is not True:
+                key = "review.%s.uploadtopic" % branch.project.remote.review
+                opt.auto_topic = branch.project.config.GetBoolean(key)
+            if opt.auto_topic:
+                opt.topic = branch.name
 
         def _ExpandCommaList(value):
             """Split |value| up into comma delimited entries."""
@@ -620,7 +628,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
         branch.UploadForReview(
             people,
             dryrun=opt.dryrun,
-            auto_topic=opt.auto_topic,
+            topic=opt.topic,
             hashtags=hashtags,
             labels=labels,
             private=opt.private,