Introduce 'repo abandon <branchname>' as an alias for 'git branch -D'

This destroys a local development branch, removing all history
of that branch from ever existing.  If the branch is currently
checked out we move back to the upstream revision.

Signed-off-by: Shawn O. Pearce <sop@google.com>

project.py

@@ -710,6 +710,22 @@ class Project(object):
     else:
       raise GitError('%s checkout %s ' % (self.name, rev))
 
+  def AbandonBranch(self, name):
+    """Destroy a local topic branch.
+    """
+    try:
+      tip_rev = self.bare_git.rev_parse(R_HEADS + name)
+    except GitError:
+      return
+
+    if self.CurrentBranch == name:
+      self._Checkout(
+        self.GetRemote(self.remote.name).ToLocal(self.revision),
+        quiet=True)
+
+    cmd = ['branch', '-D', name]
+    GitCommand(self, cmd, capture_stdout=True).Wait()
+
   def PruneHeads(self):
     """Prune any topic branches already merged into upstream.
     """

subcmds/abandon.py

@@ -0,0 +1,42 @@
+#
+# Copyright (C) 2008 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+from command import Command
+from git_command import git
+
+class Abandon(Command):
+  common = True
+  helpSummary = "Permanently abandon a development branch"
+  helpUsage = """
+%prog <branchname> [<project>...]
+
+This subcommand permanently abandons a development branch by
+deleting it (and all its history) from your local repository.
+
+It is equivalent to "git branch -D <branchname>".
+"""
+
+  def Execute(self, opt, args):
+    if not args:
+      self.Usage()
+
+    nb = args[0]
+    if not git.check_ref_format('heads/%s' % nb):
+      print >>sys.stderr, "error: '%s' is not a valid name" % nb
+      sys.exit(1)
+
+    for project in self.GetProjects(args[1:]):
+      project.AbandonBranch(nb)