Send reviews to a different branch from fetch

This adds the ability to have reviews pushed to a different branch
from the one on which changes are based. This is useful for "gateway"
systems without smartsync.

Change-Id: I3a8a0fabcaf6055e62d3fb55f89c944e2f81569f

4 files changed, 50 insertions, 20 deletions

diff --git a/docs/manifest-format.txt b/docs/manifest-format.txt
index 59f6a2fd..dcc90d07 100644
--- a/docs/manifest-format.txt
+++ b/docs/manifest-format.txt
@@ -37,24 +37,26 @@ following DTD:
     <!ATTLIST remote review       CDATA #IMPLIED>
   
     <!ELEMENT default (EMPTY)>
-    <!ATTLIST default remote   IDREF #IMPLIED>
-    <!ATTLIST default revision CDATA #IMPLIED>
-    <!ATTLIST default sync-j   CDATA #IMPLIED>
-    <!ATTLIST default sync-c   CDATA #IMPLIED>
-    <!ATTLIST default sync-s   CDATA #IMPLIED>
+    <!ATTLIST default remote      IDREF #IMPLIED>
+    <!ATTLIST default revision    CDATA #IMPLIED>
+    <!ATTLIST default dest-branch CDATA #IMPLIED>
+    <!ATTLIST default sync-j      CDATA #IMPLIED>
+    <!ATTLIST default sync-c      CDATA #IMPLIED>
+    <!ATTLIST default sync-s      CDATA #IMPLIED>
 
     <!ELEMENT manifest-server (EMPTY)>
     <!ATTLIST url              CDATA #REQUIRED>
   
     <!ELEMENT project (annotation?,
                        project*)>
-    <!ATTLIST project name     CDATA #REQUIRED>
-    <!ATTLIST project path     CDATA #IMPLIED>
-    <!ATTLIST project remote   IDREF #IMPLIED>
-    <!ATTLIST project revision CDATA #IMPLIED>
-    <!ATTLIST project groups   CDATA #IMPLIED>
-    <!ATTLIST project sync-c   CDATA #IMPLIED>
-    <!ATTLIST project sync-s   CDATA #IMPLIED>
+    <!ATTLIST project name        CDATA #REQUIRED>
+    <!ATTLIST project path        CDATA #IMPLIED>
+    <!ATTLIST project remote      IDREF #IMPLIED>
+    <!ATTLIST project revision    CDATA #IMPLIED>
+    <!ATTLIST project dest-branch CDATA #IMPLIED>
+    <!ATTLIST project groups      CDATA #IMPLIED>
+    <!ATTLIST project sync-c      CDATA #IMPLIED>
+    <!ATTLIST project sync-s      CDATA #IMPLIED>
     <!ATTLIST project upstream CDATA #IMPLIED>
     <!ATTLIST project clone-depth CDATA #IMPLIED>
     <!ATTLIST project force-path CDATA #IMPLIED>
@@ -125,6 +127,11 @@ Attribute `revision`: Name of a Git branch (e.g. `master` or
 `refs/heads/master`).  Project elements lacking their own
 revision attribute will use this revision.
 
+Attribute `dest-branch`: Name of a Git branch (e.g. `master`).
+Project elements not setting their own `dest-branch` will inherit
+this value. If this value is not set, projects will use `revision`
+by default instead.
+
 Attribute `sync_j`: Number of parallel jobs to use when synching.
 
 Attribute `sync_c`: Set to true to only sync the given Git
@@ -203,6 +210,11 @@ Tags and/or explicit SHA-1s should work in theory, but have not
 been extensively tested.  If not supplied the revision given by
 the default element is used.
 
+Attribute `dest-branch`: Name of a Git branch (e.g. `master`).
+When using `repo upload`, changes will be submitted for code
+review on this branch. If unspecified both here and in the
+default element, `revision` is used instead.
+
 Attribute `groups`: List of groups to which this project belongs,
 whitespace or comma separated.  All projects belong to the group
 "all", and each project automatically belongs to a group of
diff --git a/manifest_xml.py b/manifest_xml.py
index 16476aa5..817a1c80 100644
--- a/manifest_xml.py
+++ b/manifest_xml.py
@@ -555,6 +555,8 @@ class XmlManifest(object):
     if d.revisionExpr == '':
       d.revisionExpr = None
 
+    d.destBranchExpr = node.getAttribute('dest-branch') or None
+
     sync_j = node.getAttribute('sync-j')
     if sync_j == '' or sync_j is None:
       d.sync_j = 1
@@ -676,6 +678,8 @@ class XmlManifest(object):
         raise ManifestParseError('invalid clone-depth %s in %s' %
                                  (clone_depth, self.manifestFile))
 
+    dest_branch = node.getAttribute('dest-branch') or self._default.destBranchExpr
+
     upstream = node.getAttribute('upstream')
 
     groups = ''
@@ -709,7 +713,8 @@ class XmlManifest(object):
                       sync_s = sync_s,
                       clone_depth = clone_depth,
                       upstream = upstream,
-                      parent = parent)
+                      parent = parent,
+                      dest_branch = dest_branch)
 
     for n in node.childNodes:
       if n.nodeName == 'copyfile':
diff --git a/project.py b/project.py
index f299297d..5a7a6ca8 100644
--- a/project.py
+++ b/project.py
@@ -157,11 +157,12 @@ class ReviewableBranch(object):
       R_HEADS + self.name,
       '--')
 
-  def UploadForReview(self, people, auto_topic=False, draft=False):
+  def UploadForReview(self, people, auto_topic=False, draft=False, dest_branch=None):
     self.project.UploadForReview(self.name,
                                  people,
                                  auto_topic=auto_topic,
-                                 draft=draft)
+                                 draft=draft,
+                                 dest_branch=dest_branch)
 
   def GetPublishedRefs(self):
     refs = {}
@@ -497,7 +498,8 @@ class Project(object):
                clone_depth = None,
                upstream = None,
                parent = None,
-               is_derived = False):
+               is_derived = False,
+               dest_branch = None):
     """Init a Project object.
 
     Args:
@@ -517,6 +519,7 @@ class Project(object):
       parent: The parent Project object.
       is_derived: False if the project was explicitly defined in the manifest;
                   True if the project is a discovered submodule.
+      dest_branch: The branch to which to push changes for review by default.
     """
     self.manifest = manifest
     self.name = name
@@ -559,6 +562,7 @@ class Project(object):
       self.work_git = None
     self.bare_git = self._GitGetByExec(self, bare=True)
     self.bare_ref = GitRefs(gitdir)
+    self.dest_branch = dest_branch
 
     # This will be filled in if a project is later identified to be the
     # project containing repo hooks.
@@ -908,7 +912,8 @@ class Project(object):
   def UploadForReview(self, branch=None,
                       people=([],[]),
                       auto_topic=False,
-                      draft=False):
+                      draft=False,
+                      dest_branch=None):
     """Uploads the named branch for code review.
     """
     if branch is None:
@@ -922,7 +927,10 @@ class Project(object):
     if not branch.remote.review:
       raise GitError('remote %s has no review url' % branch.remote.name)
 
-    dest_branch = branch.merge
+    if dest_branch is None:
+      dest_branch = self.dest_branch
+    if dest_branch is None:
+      dest_branch = branch.merge
     if not dest_branch.startswith(R_HEADS):
       dest_branch = R_HEADS + dest_branch
 
diff --git a/subcmds/upload.py b/subcmds/upload.py
index 13b87784..4a22e26a 100644
--- a/subcmds/upload.py
+++ b/subcmds/upload.py
@@ -146,6 +146,10 @@ Gerrit Code Review:  http://code.google.com/p/gerrit/
     p.add_option('-d', '--draft',
                  action='store_true', dest='draft', default=False,
                  help='If specified, upload as a draft.')
+    p.add_option('-D', '--destination', '--dest',
+                 type='string', action='store', dest='dest_branch',
+                 metavar='BRANCH',
+                 help='Submit for review on this target branch.')
 
     # Options relating to upload hook.  Note that verify and no-verify are NOT
     # opposites of each other, which is why they store to different locations.
@@ -185,7 +189,8 @@ Gerrit Code Review:  http://code.google.com/p/gerrit/
       date = branch.date
       commit_list = branch.commits
 
-      print('Upload project %s/ to remote branch %s:' % (project.relpath, project.revisionExpr))
+      destination = project.dest_branch or project.revisionExpr
+      print('Upload project %s/ to remote branch %s:' % (project.relpath, destination))
       print('  branch %s (%2d commit%s, %s):' % (
                     name,
                     len(commit_list),
@@ -336,7 +341,7 @@ Gerrit Code Review:  http://code.google.com/p/gerrit/
           key = 'review.%s.uploadtopic' % branch.project.remote.review
           opt.auto_topic = branch.project.config.GetBoolean(key)
 
-        branch.UploadForReview(people, auto_topic=opt.auto_topic, draft=opt.draft)
+        branch.UploadForReview(people, auto_topic=opt.auto_topic, draft=opt.draft, dest_branch=opt.dest_branch)
         branch.uploaded = True
       except UploadError as e:
         branch.error = e