init: change --depth default to 1 for manifest repo

People rarely care about the history of the manifest repo.  Change
the default to 1 to speed up initial setup.  If people really want
the full history, they can pass --manifest-depth=0.

We can't reuse the existing --depth option because that applies to
all projects we clone, not just the manifest repo.

Bug: https://crbug.com/gerrit/16193
Change-Id: Ideab1712e9ffc743b9bae97903e074d7d429b134
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/343435
Tested-by: Mike Frysinger <[email protected]>
Reviewed-by: LaMont Jones <[email protected]>

man/repo-gitc-init.1

@@ -45,6 +45,10 @@ sync any submodules associated with the manifest repo
 \fB\-\-standalone\-manifest\fR
 download the manifest as a static file rather then
 create a git checkout of the manifest repo
+.TP
+\fB\-\-manifest\-depth\fR=\fI\,DEPTH\/\fR
+create a shallow clone of the manifest repo with given
+depth; see git clone (default: 1)
 .SS Manifest (only) checkout options:
 .TP
 \fB\-\-current\-branch\fR

man/repo-init.1

@@ -45,6 +45,10 @@ sync any submodules associated with the manifest repo
 \fB\-\-standalone\-manifest\fR
 download the manifest as a static file rather then
 create a git checkout of the manifest repo
+.TP
+\fB\-\-manifest\-depth\fR=\fI\,DEPTH\/\fR
+create a shallow clone of the manifest repo with given
+depth; see git clone (default: 1)
 .SS Manifest (only) checkout options:
 .TP
 \fB\-c\fR, \fB\-\-current\-branch\fR

repo

@@ -316,6 +316,9 @@ def InitParser(parser, gitc_init=False):
                    help='download the manifest as a static file '
                         'rather then create a git checkout of '
                         'the manifest repo')
+  group.add_option('--manifest-depth', type='int', default=1, metavar='DEPTH',
+                   help='create a shallow clone of the manifest repo with '
+                        'given depth; see git clone (default: %default)')
 
   # Options that only affect manifest project, and not any of the projects
   # specified in the manifest itself.

subcmds/init.py

@@ -109,6 +109,10 @@ def _SyncManifest(self, opt):
     Args:
       opt: options from optparse.
     """
+    # Normally this value is set when instantiating the project, but the
+    # manifest project is special and is created when instantiating the
+    # manifest which happens before we parse options.
+    self.manifest.manifestProject.clone_depth = opt.manifest_depth
     if not self.manifest.manifestProject.Sync(
         manifest_url=opt.manifest_url,
         manifest_branch=opt.manifest_branch,