Fix gclient branch ref mangling and allow --force branch switches.

gclient_scm.py

Index: gclient_scm.py
diff --git a/gclient_scm.py b/gclient_scm.py
index 88760932f2a1c30e5da1aae4c2da9353cea977e3..3015d0d8d4d618a28bb9f5e769b0979b63412e96 100644
--- a/gclient_scm.py
+++ b/gclient_scm.py
@@ -369,7 +369,8 @@ class GitWrapper(SCMWrapper):
       verbose = ['--verbose']
       printed_path = True
 
-    if revision.startswith('refs/'):
+    remote_ref = scm.GIT.RefToRemoteRef(revision, self.remote)
+    if revision.startswith('refs/') or remote_ref:
       rev_type = "branch"
     elif revision.startswith(self.remote + '/'):
       # Rewrite remote refs to their local equivalents.
@@ -393,8 +394,8 @@ class GitWrapper(SCMWrapper):
       except subprocess2.CalledProcessError:
         self._DeleteOrMove(options.force)
         self._Clone(revision, url, options)
-      if deps_revision and deps_revision.startswith('branch-heads/'):
-        deps_branch = deps_revision.replace('branch-heads/', '')
+      if remote_ref:
+        deps_branch = remote_ref[1]
         self._Capture(['branch', deps_branch, deps_revision])
         self._Checkout(options, deps_branch, quiet=True)
       if file_list is not None:
@@ -451,12 +452,16 @@ class GitWrapper(SCMWrapper):
     # 2) current branch is tracking a remote branch with local committed
     #    changes, but the DEPS file switched to point to a hash
     #   - rebase those changes on top of the hash
-    # 3) current branch is tracking a remote branch w/or w/out changes,
-    #    no switch
+    # 3) current branch is tracking a remote branch w/or w/out changes, and
+    #    no DEPS switch
     #   - see if we can FF, if not, prompt the user for rebase, merge, or stop
-    # 4) current branch is tracking a remote branch, switches to a different
-    #    remote branch
-    #   - exit
+    # 4) current branch is tracking a remote branch, but DEPS switches to a
+    #    different remote branch, and
+    #   a) current branch has no local changes, and --force:
+    #      - checkout new branch
+    #   b) current branch has local changes, and --force and --reset:
+    #      - checkout new branch
+    #   c) otherwise exit
 
     # GetUpstreamBranch returns something like 'refs/remotes/origin/master' for
     # a tracking branch
@@ -534,17 +539,38 @@ class GitWrapper(SCMWrapper):
                           newbase=revision, printed_path=printed_path,
                           merge=options.merge)
       printed_path = True
-    elif revision.replace('heads', 'remotes/' + self.remote) != upstream_branch:
+    elif remote_ref and ''.join(remote_ref) != upstream_branch:
       # case 4
-      new_base = revision.replace('heads', 'remotes/' + self.remote)
+      new_base = ''.join(remote_ref)
       if not printed_path:
         self.Print('_____ %s%s' % (self.relpath, rev_str), timestamp=False)
-      switch_error = ("Switching upstream branch from %s to %s\n"
+      switch_error = ("Could not switch upstream branch from %s to %s\n"
                      % (upstream_branch, new_base) +
-                     "Please merge or rebase manually:\n" +
+                     "Please use --force or merge or rebase manually:\n" +
                      "cd %s; git rebase %s\n" % (self.checkout_path, new_base) +
                      "OR git checkout -b <some new branch> %s" % new_base)
-      raise gclient_utils.Error(switch_error)
+      force_switch = False
+      if options.force:
+        try:
+          self._CheckClean(rev_str)
+          # case 4a
+          force_switch = True
+        except gclient_utils.Error as e:
+          if options.reset:
+            # case 4b
+            force_switch = True
+          else:
+            switch_error = '%s\n%s' % (e.message, switch_error)
+      if force_switch:
+        self.Print("Switching upstream branch from %s to %s" %
+                   (upstream_branch, new_base))
+        switch_branch = 'gclient_' + remote_ref[1]
+        self._Capture(['branch', '-f', switch_branch, new_base])
+        self._Checkout(options, switch_branch, force=True, quiet=True)
+        pass

[iannucci, 2014/09/06 20:01:29]

pass not needed?

[Michael Moss, 2014/09/08 23:58:42]

Done.

+      else:
+        # case 4c
+        raise gclient_utils.Error(switch_error)

[iannucci, 2014/09/06 20:01:29]

why not raise this directly in the else case above?

[Michael Moss, 2014/09/08 23:58:43]

That's in the options.force block, so it would never be seen without --force.

     else:
       # case 3 - the default case
       if files is not None: