Stop setting a default topic on new changes

Recent releases of Gerrit have evolved their use of the "topic"
functionality.  Originally it was there merely for the convenince
of users.  It could be used to make a group of related or similar
changes easy to query.  In current releases of Gerrit, it serves
a much more deliberate purpose: if submitWholeTopic is enabled,
then merging one change in a topic will merge all of them
simultaneously.

Since this has very significant impacts to developer workflow,
git-review should no longer set a topic unless it is explicitly
requested by a user.

This change alters the behavior of git-review so that it will no
longer set a topic unless explicitly set by a user.  It also
deprecates the 'notopic' and '-T' options.  They are retained for
backwards compatability with existing scripts, but no longer have
any effect.

Change-Id: Ib83981a4952e1d6d68ebb8add11aabefbf3b2a4b

doc/source/usage.rst

@@ -16,16 +16,12 @@ If you want to submit to a different remote::
 
 If you want to supply a review topic::
 
-    git review -t topic/awesome-feature
+    git review -t awesome-feature
 
 If you want to subscribe some reviewers::
 
     git review --reviewers a@example.com b@example.com
 
-If you want to disable autogenerated topic::
-
-    git review -T
-
 If you want to submit a branch for review and then remove the local branch::
 
     git review -f

git-review.1

@@ -72,7 +72,7 @@ The following options are available:
 Download
 .Ar change
 from Gerrit
-into a local branch. The branch will be named after the patch author and the name of a topic.
+into a local branch. The branch will be named after the change number.
 If the local branch already exists, it will attempt to update with the latest patchset for this change.
 .It Fl x Ar change , Fl \-cherrypick= Ns Ar change
 Apply
@@ -156,9 +156,8 @@ the built-in version.
 Just run the repo setup commands but don\(aqt submit anything.
 .It Fl t Ar topic , Fl \-topic= Ns Ar topic
 Sets the target topic for this change on the Gerrit server.
-If not specified, a bug number from the commit summary will be used. Alternatively, the local branch name will be used if different from remote branch.
 .It Fl T , Fl \-no\-topic
-Submit review without topic.
+Submit review without topic (the default).
 .It Fl \-hashtags= Ns Ar taglist
 Comma-separated list of hashtag strings for this change, no spaces allowed.
 .It Fl \-message= Ns Ar message
@@ -264,7 +263,10 @@ This setting determines the default name to use for gerrit remote
 .It gitreview.branch
 This setting determines the default branch
 .It gitreview.notopic
-Set to true to never submit with a default topic
+Set to true to never submit with a default topic (deprecated).
+This is the default behavior and this option has no effect.  It is
+kept for backwards compatability and may be removed in a future
+version of git-review.
 .It gitreview.track
 Determines whether to prefer the currently-tracked branch (if any)
 and the branch against which the changeset was submitted to Gerrit
@@ -466,26 +468,23 @@ To fetch a remote change number 3004:
 .Bd -literal -offset indent
 $ git\-review \-d 3004
 Downloading refs/changes/04/3004/1 from gerrit into
-review/someone/topic_name
-Switched to branch 'review/someone/topic_name
+review/3004
+Switched to branch 'review/3004
 $ git branch
   master
-* review/author/topic_name
+* review/3004
 .Ed
 .Pp
-Gerrit looks up both name of the author and the topic name from Gerrit
-to name a local branch. This facilitates easier identification of changes.
-.Pp
 To fetch a remote patchset number 5 from change number 3004:
 .Pp
 .Bd -literal -offset indent
 $ git\-review \-d 3004,5
 Downloading refs/changes/04/3004/5 from gerrit into
-review/someone/topic_name\-patch5
-Switched to branch 'review/someone/topic_name\-patch5
+review/3004\-patch5
+Switched to branch 'review/3004\-patch5
 $ git branch
   master
-* review/author/topic_name\-patch5
+* review/3004\-patch5
 .Ed
 .Pp
 To send a change for review and delete local branch afterwards:
@@ -493,9 +492,9 @@ To send a change for review and delete local branch afterwards:
 $ git\-review \-f
 remote: Resolving deltas:   0% (0/8)
 To ssh://username@review.example.com/department/project.git
- * [new branch]      HEAD \-> refs/for/master/topic_name
+ * [new branch]      HEAD \-> refs/for/master
 Switched to branch 'master'
-Deleted branch 'review/someone/topic_name'
+Deleted branch 'review/somenumber'
 $ git branch
 * master
 .Ed

git_review/cmd.py

@@ -54,7 +54,7 @@ GLOBAL_CONFIG = "/etc/git-review/git-review.conf"
 USER_CONFIG = os.path.join(CONFIGDIR, "git-review.conf")
 DEFAULTS = dict(scheme='ssh', hostname=False, port=None, project=False,
                 branch='master', remote="gerrit", rebase="1",
-                track="0", usepushurl="0", notopic=False, branchauthor="name")
+                track="0", usepushurl="0", notopic=True, branchauthor="name")
 LOCAL_GIT_VERSION = (0, 0, 0)
 COPYRIGHT = """\
 Copyright OpenStack Foundation and OpenDev Contributors
@@ -1099,27 +1099,6 @@ def assert_one_change(remote, branch, yes, have_hook):
                 sys.exit(1)
 
 
-def get_topic(target_branch):
-    branch_name = get_branch_name(target_branch)
-
-    branch_parts = branch_name.split("/")
-    if len(branch_parts) >= 3 and branch_parts[0] == "review":
-        # We don't want to set the review number as the topic
-        if branch_parts[2].isdigit():
-            return
-
-        topic = "/".join(branch_parts[2:])
-        if VERBOSE:
-            print("Using change number %s for the topic of the change "
-                  "submitted" % topic)
-        return topic
-
-    if VERBOSE:
-        print("Using local branch name %s for the topic of the change "
-              "submitted" % branch_name)
-    return branch_name
-
-
 class CannotQueryOpenChangesets(CommandFailed):
     "Cannot fetch review information from gerrit"
     EXIT_CODE = 32
@@ -1337,23 +1316,14 @@ def fetch_review(review, masterbranch, remote, project):
     except KeyError:
         raise ReviewNotFound(review)
 
-    try:
-        topic = review_info['topic']
-        if topic == masterbranch:
-            topic = review
-    except KeyError:
-        topic = review
-    try:
-        author = re.sub(r'\W+', '_',
-                        review_info['owner'][BRANCHAUTHOR]).lower()
-    except KeyError:
-        author = 'unknown'
+    change_number = review_info.get('number',
+                                    review_info.get('_number', review))
     remote_branch = review_info['branch']
 
     if patchset_number is None:
-        branch_name = "review/%s/%s" % (author, topic)
+        branch_name = "review/%s" % (change_number,)
     else:
-        branch_name = "review/%s/%s-patch%s" % (author, topic, patchset_number)
+        branch_name = "review/%s-patch%s" % (change_number, patchset_number)
 
     print("Downloading %s from gerrit" % refspec)
     run_command_exc(PatchSetGitFetchFailed,
@@ -1591,7 +1561,8 @@ additional information:
                                  help="Topic to submit branch to")
     topic_arg_group.add_argument("-T", "--no-topic", dest="notopic",
                                  action="store_true",
-                                 help="No topic except if explicitly provided")
+                                 help="No topic except if explicitly provided"
+                                 " (deprecated)")
 
     parser.add_argument("--hashtags", nargs="+",
                         help="Hashtags to submit branch to")
@@ -1876,7 +1847,7 @@ additional information:
     if options.topic is not None:
         topic = options.topic
     else:
-        topic = None if options.notopic else get_topic(branch)
+        topic = None
 
     if topic and topic != branch:
         push_options.append("topic=%s" % topic)

git_review/tests/test_git_review.py

@@ -560,18 +560,19 @@ class GitReviewTestCase(tests.BaseGitReviewTestCase):
                                      extra_args=['-t', 'zat'])
 
     def test_git_review_T(self):
+        # This option is deprecated and kept for compatibility; the
+        # only behavior now is "notopic".
         self._run_git_review('-s')
         self._run_git('checkout', '-b', 'bug/456')
         self._simple_change('test file modified', 'commit message for bug 456')
-        self._assert_branch_would_be('master%topic=bug/456')
+        self._assert_branch_would_be('master')
         self._assert_branch_would_be('master', extra_args=['-T'])
 
         self._run_git('config', 'gitreview.notopic', 'true')
         self._assert_branch_would_be('master')
         self._run_git('config', 'gitreview.notopic', 'false')
-        self._assert_branch_would_be('master%topic=bug/456')
+        self._assert_branch_would_be('master')
 
-        # -T takes precedence over notopic=false
         self._assert_branch_would_be('master', extra_args=['-T'])
 
     def test_git_review_T_t(self):

releasenotes/notes/deprecate-notopic-b198a4b51e8624b2.yaml

@@ -0,0 +1,15 @@
+---
+upgrade:
+  - |
+    Git-review no longer supplies a default topic when uploading a new
+    change.  The only way to set a topic on a newly uploaded change is
+    to use the ``-t <topic>`` option.
+  - |
+    When downloading changes using ``git-review -d``, the local branch
+    name is now based on the change number rather than the author and
+    topic.
+deprecations:
+  - |
+    The ``gitreview.notopic`` configuration setting and ``-T`` command line
+    option are deprecated and no longer have any effect.  The default behavior
+    is now as if ``notopic`` is set.