combo-layer: support updating up to arbitrary commit

Support defining the top commit up to which to update. In other words,
this makes it possible to update up to certain point other than the
branch head. The update point (git commitish) is given on the command
line by appending the component name(s) with a colon and the commitish,
e.g.
 $ combo-layer update my_component:sha1

Only the "update" action supports this.

(From OE-Core rev: b7ee7cf5bbfd0f305a75e4df9455f9968aa67878)

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/combo-layer

@@ -26,6 +26,7 @@ import logging
 import subprocess
 import ConfigParser
 import re
+from collections import OrderedDict
 
 __version__ = "0.2.1"
 
@@ -347,7 +348,13 @@ def action_update(conf, args):
         generate the patch list
         apply the generated patches
     """
-    repos = get_repos(conf, args[1:])
+    components = [arg.split(':')[0] for arg in args[1:]]
+    revisions = []
+    for arg in args[1:]:
+        revision= arg.split(':', 1)[1] if ':' in arg else None
+        revisions.append(revision)
+    # Map commitishes to repos
+    repos = OrderedDict(zip(get_repos(conf, components), revisions))
 
     # make sure combo repo is clean
     check_repo_clean(os.getcwd())
@@ -361,9 +368,9 @@ def action_update(conf, args):
     if conf.nopull:
         logger.info("Skipping pull (-n)")
     else:
-        action_pull(conf, args)
+        action_pull(conf, ['arg0'] + components)
 
-    for name in repos:
+    for name, revision in repos.iteritems():
         repo = conf.repos[name]
         ldir = repo['local_repo_dir']
         dest_dir = repo['dest_dir']
@@ -372,18 +379,21 @@ def action_update(conf, args):
 
         # Step 2: generate the patch list and store to patch dir
         logger.info("Generating patches from %s..." % name)
+        top_revision = revision or branch
+        if not check_rev_branch(name, ldir, top_revision, branch):
+            sys.exit(1)
         if dest_dir != ".":
             prefix = "--src-prefix=a/%s/ --dst-prefix=b/%s/" % (dest_dir, dest_dir)
         else:
             prefix = ""
         if repo['last_revision'] == "":
             logger.info("Warning: last_revision of component %s is not set, starting from the first commit" % name)
-            patch_cmd_range = "--root %s" % branch
-            rev_cmd_range = branch
+            patch_cmd_range = "--root %s" % top_revision
+            rev_cmd_range = top_revision
         else:
             if not check_rev_branch(name, ldir, repo['last_revision'], branch):
                 sys.exit(1)
-            patch_cmd_range = "%s..%s" % (repo['last_revision'], branch)
+            patch_cmd_range = "%s..%s" % (repo['last_revision'], top_revision)
             rev_cmd_range = patch_cmd_range
 
         file_filter = repo.get('file_filter',"")