Introduce manifest format using git submodules

If a manifest top level directory contains '.gitmodules' we now
assume this is a git module format manifest and switch to using
that code, rather than the legacy XML based manifest.

At the same time, we move the bare repository for a project from
$TOP/.repo/projects/$REPO_PATH.git to be $REPO_NAME.git instead.
This makes it easier for us to later support a repo init from an
existing work tree, as we can more accurately predict the path of
the project's repository in the workspace.  It also means that the
$TOP/.repo/projects/ directory is layed out like a mirror would be.

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

subcmds/init.py

@@ -21,6 +21,7 @@ from command import InteractiveCommand, MirrorSafeCommand
 from error import ManifestParseError
 from project import SyncBuffer
 from git_command import git_require, MIN_GIT_VERSION
+from manifest_submodule import SubmoduleManifest
 from manifest_xml import XmlManifest
 from subcmds.sync import _ReloadManifest
 
@@ -144,6 +145,14 @@ to update the working directory files.
       print >>sys.stderr, 'fatal: cannot obtain manifest %s' % r.url
       sys.exit(1)
 
+    if is_new and SubmoduleManifest.IsBare(m):
+      new = self.GetManifest(reparse=True, type=SubmoduleManifest)
+      if m.gitdir != new.manifestProject.gitdir:
+        os.rename(m.gitdir, new.manifestProject.gitdir)
+        new = self.GetManifest(reparse=True, type=SubmoduleManifest)
+      m = new.manifestProject
+      self._ApplyOptions(opt, is_new)
+
     if not is_new:
       # Force the manifest to load if it exists, the old graph
       # may be needed inside of _ReloadManifest().

subcmds/manifest.py

@@ -22,7 +22,7 @@ from manifest_xml import XmlManifest
 def _doc(name):
   r = os.path.dirname(__file__)
   r = os.path.dirname(r)
-  fd = open(os.path.join(r, 'docs', 'manifest_xml.txt'))
+  fd = open(os.path.join(r, 'docs', name))
   try:
     return fd.read()
   finally:
@@ -48,6 +48,8 @@ in a Git repository for use during future 'repo init' invocations.
     help = ''
     if isinstance(self.manifest, XmlManifest):
       help += self._xmlHelp + '\n' + _doc('manifest_xml.txt')
+    if isinstance(self.manifest, SubmoduleManifest):
+      help += _doc('manifest_submodule.txt')
     return help
 
   def _Options(self, p):