[jhbuild] Support option "shallow_clone" in bazaar (as lightweight checkout)

[Craig Keogh <cskeogh src gnome org>]

commit 6946b6a8c7ea1a3b3b023028863d9a40811f90e3
Author: Marcin Wojdyr <wojdyr gmail com>
Date:   Thu May 16 18:13:22 2013 +0100

    Support option "shallow_clone" in bazaar (as lightweight checkout)

 jhbuild/defaults.jhbuildrc    |    2 +-
 jhbuild/versioncontrol/bzr.py |   17 +++++++++++++----
 2 files changed, 14 insertions(+), 5 deletions(-)
---
diff --git a/jhbuild/defaults.jhbuildrc b/jhbuild/defaults.jhbuildrc
index c208ab6..e467a49 100644
--- a/jhbuild/defaults.jhbuildrc
+++ b/jhbuild/defaults.jhbuildrc
@@ -198,7 +198,7 @@ ignore_suggests = False
 
 # local directory for DVCS mirror (git only atm)
 dvcs_mirror_dir = None
-# If true, use --depth=1 to git
+# If true, use --depth=1 to git and bzr checkout --light
 shallow_clone = False
 
 # A string displayed before JHBuild executes a command. String may contain the
diff --git a/jhbuild/versioncontrol/bzr.py b/jhbuild/versioncontrol/bzr.py
index 9a43d3b..284e12a 100644
--- a/jhbuild/versioncontrol/bzr.py
+++ b/jhbuild/versioncontrol/bzr.py
@@ -185,7 +185,11 @@ Remove it or change your dvcs_mirror_dir settings.""") % self.srcdir)
             self.create_mirror(buildscript)
             self.real_update(buildscript)
         else:
-            cmd = ['bzr', 'branch'] + self.revspec + [self.module, self.srcdir]
+            if self.config.shallow_clone:
+                cmd = ['bzr', 'co', '--light']
+            else:
+                cmd = ['bzr', 'branch']
+            cmd += self.revspec + [self.module, self.srcdir]
             buildscript.execute(cmd)
 
     def _export(self, buildscript):
@@ -193,9 +197,14 @@ Remove it or change your dvcs_mirror_dir settings.""") % self.srcdir)
         buildscript.execute(cmd)
 
     def real_update(self, buildscript):
-        cmd = ['bzr', 'pull'] + self.revspec + [self.module, '-d', self.srcdir]
-        buildscript.execute(cmd)
-        cmd = ['bzr', 'update'] + self.revspec + [self.srcdir]
+        # Do not assume that shallow_clone option was the same
+        # during checkout as now.
+        info = get_output(['bzr', 'info', self.srcdir], cwd=self.srcdir)
+        if info.startswith('Light'):
+            cmd = ['bzr', 'update'] + self.revspec
+        else:
+            cmd = ['bzr', 'pull'] + self.revspec + [self.module]
+        buildscript.execute(cmd, cwd=self.srcdir)
 
     def _update(self, buildscript, copydir=None):
         self.create_mirror(buildscript)