download: support -x when cherry-picking

This is a pretty common option for people to want too use, so include
it as a pass-thru option when cherry-picking.

Bug: https://crbug.com/gerrit/9418
Change-Id: I2a24c1ed7544541719caa4d3c0574347a151a1b0
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/259853
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>

project.py

@@ -2681,10 +2681,12 @@ class Project(object):
       if self._allrefs:
         raise GitError('%s checkout %s ' % (self.name, rev))
 
-  def _CherryPick(self, rev, ffonly=False):
+  def _CherryPick(self, rev, ffonly=False, record_origin=False):
     cmd = ['cherry-pick']
     if ffonly:
       cmd.append('--ff')
+    if record_origin:
+      cmd.append('-x')
     cmd.append(rev)
     cmd.append('--')
     if GitCommand(self, cmd).Wait() != 0:

subcmds/download.py

@@ -40,6 +40,8 @@ If no project is specified try to use current directory as a project.
     p.add_option('-c', '--cherry-pick',
                  dest='cherrypick', action='store_true',
                  help="cherry-pick instead of checkout")
+    p.add_option('-x', '--record-origin', action='store_true',
+                 help='pass -x when cherry-picking')
     p.add_option('-r', '--revert',
                  dest='revert', action='store_true',
                  help="revert instead of checkout")
@@ -78,6 +80,14 @@ If no project is specified try to use current directory as a project.
         project = self.GetProjects([a])[0]
     return to_get
 
+  def ValidateOptions(self, opt, args):
+    if opt.record_origin:
+      if not opt.cherrypick:
+        self.OptionParser.error('-x only makes sense with --cherry-pick')
+
+      if opt.ffonly:
+        self.OptionParser.error('-x and --ff are mutually exclusive options')
+
   def Execute(self, opt, args):
     for project, change_id, ps_id in self._ParseChangeIds(args):
       dl = project.DownloadPatchSet(change_id, ps_id)
@@ -101,7 +111,8 @@ If no project is specified try to use current directory as a project.
           print('  %s' % (c), file=sys.stderr)
       if opt.cherrypick:
         try:
-          project._CherryPick(dl.commit, ffonly=opt.ffonly)
+          project._CherryPick(dl.commit, ffonly=opt.ffonly,
+                              record_origin=opt.record_origin)
         except GitError:
           print('[%s] Could not complete the cherry-pick of %s'
                 % (project.name, dl.commit), file=sys.stderr)