[gnome-continuous-yocto/gnomeostree-3.28-rocko: 6744/8267] wic: isoimage-isohybrid: check result of glob()

[Emmanuele Bassi <ebassi src gnome org>]

commit f58ea8c81412344cae268960d13b968901f19577
Author: Ed Bartosh <ed bartosh linux intel com>
Date:   Fri Jul 14 15:33:03 2017 +0300

    wic: isoimage-isohybrid: check result of glob()
    
    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.
    
    (From OE-Core rev: ad02f253f08a3da3fa5c86ae4f6ba7f94b070578)
    
    Signed-off-by: Ed Bartosh <ed bartosh linux intel com>
    Signed-off-by: Ross Burton <ross burton intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 .../lib/wic/plugins/source/isoimage-isohybrid.py   |    7 +++++--
 1 files 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