[OE-core] [PATCH 3/3] combo-layer: fix file_exclude for empty commits

[Patrick Ohly]

The code detecting empty patches after removing files with
file_exclude failed for commits which were already empty before (like
the initial commit in some repos): such patches are completely empty
files, without a From line.

Detect that case and just let the normal empty patch detection deal
with it.

Signed-off-by: Patrick Ohly <patrick.ohly at intel.com>
---
 scripts/combo-layer | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/scripts/combo-layer b/scripts/combo-layer
index a1fc6ac..1dce4a6 100755
--- a/scripts/combo-layer
+++ b/scripts/combo-layer
@@ -665,6 +665,10 @@ def action_update(conf, args):
                     # Empty, ignore it. Must also remove from revlist.
                     with open(patch, 'r') as f:
                         fromline = f.readline()
+                    if not fromline:
+                        # Patch must have been empty to start with. No need
+                        # to remove it.
+                        continue
                     m = re.match(r'''^From ([0-9a-fA-F]+) .*\n''', fromline)
                     rev = m.group(1)
                     logger.debug('skipping empty patch %s = %s' % (patch, rev))
-- 
2.1.4