update.py: fix layer exists-on-branch check

There was a logic error here - we were checking to see if the layer
directory existed before actually checking out the branch, which means
we were looking at the state of whatever branch was previously checked
out. Replace this with some validation of the last revision check and an
additional check for the directory after checking out the branch.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

1 files changed, 21 insertions, 13 deletions

diff --git a/layerindex/update.py b/layerindex/update.py
index 5670d6272b..d194f86072 100755
--- a/layerindex/update.py
+++ b/layerindex/update.py
@@ -273,8 +273,10 @@ def main():
                     transaction.rollback()
                     continue
 
+                newbranch = False
                 if not layerbranch:
                     # LayerBranch doesn't exist for this branch, create it
+                    newbranch = True
                     layerbranch = LayerBranch()
                     layerbranch.layer = layer
                     layerbranch.branch = branch
@@ -283,12 +285,6 @@ def main():
                         layerbranch_source = layer.get_layerbranch(None)
                     if layerbranch_source:
                         layerbranch.vcs_subdir = layerbranch_source.vcs_subdir
-                        if layerbranch.vcs_subdir:
-                            checksubdir = os.path.join(repodir, layerbranch.vcs_subdir)
-                            if not os.path.exists(checksubdir):
-                                logger.info("Skipping update of layer %s for branch %s - subdirectory %s does not exist on this branch" % (layer.name, branchdesc, layerbranch.vcs_subdir))
-                                transaction.rollback()
-                                continue
                     layerbranch.save()
                     if layerbranch_source:
                         for maintainer in layerbranch_source.layermaintainer_set.all():
@@ -305,9 +301,19 @@ def main():
                 if layerbranch.vcs_subdir and not options.nocheckout:
                     # Find latest commit in subdirectory
                     # A bit odd to do it this way but apparently there's no other way in the GitPython API
-                    for commit in repo.iter_commits('origin/%s' % branchname, paths=layerbranch.vcs_subdir):
-                        topcommit = commit
-                        break
+                    topcommit = next(repo.iter_commits('origin/%s' % branchname, paths=layerbranch.vcs_subdir), None)
+                    if not topcommit:
+                        # This will error out if the directory is completely invalid or had never existed at this point
+                        # If it previously existed but has since been deleted, you will get the revision where it was
+                        # deleted - so we need to handle that case separately later
+                        if newbranch:
+                            logger.info("Skipping update of layer %s for branch %s - subdirectory %s does not exist on this branch" % (layer.name, branchdesc, layerbranch.vcs_subdir))
+                        elif layerbranch.vcs_subdir:
+                            logger.error("Subdirectory for layer %s does not exist on branch %s - if this is legitimate, the layer branch record should be deleted" % (layer.name, branchdesc))
+                        else:
+                            logger.error("Failed to get last revision for layer %s on branch %s" % (layer.name, branchdesc))
+                        transaction.rollback()
+                        continue
 
                 layerdir = os.path.join(repodir, layerbranch.vcs_subdir)
                 layerdir_start = os.path.normpath(layerdir) + os.sep
@@ -321,11 +327,13 @@ def main():
                         out = utils.runcmd("git checkout origin/%s" % branchname, repodir, logger=logger)
                         out = utils.runcmd("git clean -f -x", repodir, logger=logger)
 
-                    if not os.path.exists(layerdir):
-                        if options.branch == 'master':
+                    if layerbranch.vcs_subdir and not os.path.exists(layerdir):
+                        if newbranch:
+                            logger.info("Skipping update of layer %s for branch %s - subdirectory %s does not exist on this branch" % (layer.name, branchdesc, layerbranch.vcs_subdir))
+                        else:
                             logger.error("Subdirectory for layer %s does not exist on branch %s - if this is legitimate, the layer branch record should be deleted" % (layer.name, branchdesc))
-                            transaction.rollback()
-                            continue
+                        transaction.rollback()
+                        continue
 
                     if not os.path.exists(os.path.join(layerdir, 'conf/layer.conf')):
                         logger.error("conf/layer.conf not found for layer %s - is subdirectory set correctly?" % layer.name)