bitbake: tinfoil: fix override handling in remote datastores

There was a huge gap in the remote datastore code introduced in the
tinfoil2 rework - we weren't handling overrides at all, since these are
stored separately from the actual data in the DataSmart object. Thus,
when a datastore actually represents a remote datastore we need to go
back to that remote datastore to get the override data as well, so
introduce code to do that.

To avoid a second round-trip I had to modify the _findVar() function to
return the override data as well. This will increase the overhead a
little when that data is superfluous, but without making the function
even uglier I don't think there's a way to avoid that.

(Bitbake rev: 4f9d6f060ed247fb6fa2f45668a892a1788d3f91)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/tests/data.py

@@ -503,3 +503,7 @@ class Remote(unittest.TestCase):
         # Test client side data is incorporated in python expansion (which is done on server)
         d2.setVar('FOO', 'bar')
         self.assertEqual(d2.expand('${@d.getVar("FOO")}'), 'bar')
+        # Test overrides work
+        d1.setVar('FOO_test', 'baz')
+        d1.appendVar('OVERRIDES', ':test')
+        self.assertEqual(d2.getVar('FOO'), 'baz')