ostbuild: Pull patches from specified patches git repository

We need to be more formal about where we get patches from, and more
specifically what version.  Let's assume they're also stored in a git
repository that we fetch, instead of copying them from "wherever the
manifest is".

This meshes nicely with splitting between manifest.json and
snapshot.json.

gnomeos/3.4/manifest.json

@@ -23,7 +23,8 @@
 		"netfilter": "git:git://git.netfilter.org/",
 		"cgwalters": "git:git://github.com/cgwalters/"},
 
-  "patches": {"src": "gnome:ostree"},
+  "patches": {"src": "gnome:ostree",
+              "prefix": "gnomeos/3.4"},
 
   "components": [
    		{"src": "cgwalters:ginitscripts"},

src/ostbuild/pyostbuild/builtin_build.py

@@ -140,8 +140,20 @@ class OstbuildBuild(builtins.Builtin):
         
         patches = meta.get('patches')
         if patches is not None:
+            patches_meta = self.manifest['patches']
+            (patches_keytype, patches_uri) = buildutil.parse_src_key(patches_meta['src'])
+            patches_mirror = buildutil.get_mirrordir(self.mirrordir, patches_keytype, patches_uri)
+            vcs.get_vcs_checkout(self.mirrordir, patches_keytype, patches_uri,
+                                 self.patchdir, patches_meta['branch'],
+                                 overwrite=True)
+
+            patch_prefix = patches_meta.get('prefix', None)
+            if patch_prefix is not None:
+                patchdir = os.path.join(self.patchdir, patch_prefix)
+            else:
+                patchdir = self.patchdir
             for patch in patches:
-                patch_path = os.path.join(self.patchdir, patch)
+                patch_path = os.path.join(patchdir, patch)
                 run_sync(['git', 'am', '--ignore-date', '-3', patch_path], cwd=component_src)
         
         logdir = os.path.join(self.workdir, 'logs', 'compile', name)

src/ostbuild/pyostbuild/builtin_resolve.py

@@ -210,23 +210,10 @@ class OstbuildResolve(builtins.Builtin):
         self.manifest['components'] = self.resolved_components
 
         out_snapshot = os.path.join(self.workdir, 'snapshot.json')
-        patchdir = os.path.join(self.workdir, 'patches')
-        if not os.path.isdir(patchdir):
-            os.mkdir(patchdir)
-        all_patches = {}
-        for component in self.resolved_components:
-            patches = component.get('patches', [])
-            for patch in patches:
-                all_patches[patch] = True
-        for patch in all_patches:
-            src = os.path.join(os.path.dirname(manifest_path),
-                               patch)
-            dest = os.path.join(patchdir, patch)
-            shutil.copy(src, dest)
 
         f = open(out_snapshot, 'w')
         json.dump(self.manifest, f, indent=4, sort_keys=True)
         f.close()
-        print "Created: %s, %d patches" % (out_snapshot, len(all_patches.keys()))
+        print "Created: %s" % (out_snapshot, )
         
 builtins.register(OstbuildResolve)