[PATCH v2 4/8] wic: isoimage-isohybrid: check result of glob()

[Ed Bartosh <ed.bartosh@linux.intel.com>]

isoimage-isohybrid plugin uses result of glob call to
get path to initrd image. When glob returns empty list
the plugin crashes with IndexError.

Checking if result of glob call is not empty should fix
the breakage.

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
---
 scripts/lib/wic/plugins/source/isoimage-isohybrid.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scripts/lib/wic/plugins/source/isoimage-isohybrid.py b/scripts/lib/wic/plugins/source/isoimage-isohybrid.py
index ffa5429..ece4b0c 100644
--- a/scripts/lib/wic/plugins/source/isoimage-isohybrid.py
+++ b/scripts/lib/wic/plugins/source/isoimage-isohybrid.py
@@ -164,9 +164,12 @@ class IsoImagePlugin(SourcePlugin):
 
             machine = os.path.basename(initrd_dir)
 
-            initrd = glob.glob('%s/%s*%s.%s' % (initrd_dir, image_name, machine, image_type))[0]
+            pattern = '%s/%s*%s.%s' % (initrd_dir, image_name, machine, image_type)
+            files = glob.glob(pattern)
+            if files:
+                initrd = files[0]
 
-        if not os.path.exists(initrd):
+        if not initrd or not os.path.exists(initrd):
             # Create initrd from rootfs directory
             initrd = "%s/initrd.cpio.gz" % cr_workdir
             initrd_dir = "%s/INITRD" % cr_workdir
-- 
2.1.4