lib/oe/recipeutils: fix patch_recipe*() with empty input

If you supplied an empty file to patch_recipe() (or an empty list to
patch_recipe_lines()) then the result was IndexError because the code
checking to see if it needed to add an extra line of padding didn't
check to see if there were in fact any lines before trying to access the
last line.

Fixes [YOCTO #9972].

(From OE-Core rev: 92a73e870478ddb2a2d137e3fff28828809bec2e)

(From OE-Core rev: 5ce14441f02894e68881807138e8f45074900ba2)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/meta/lib/oe/recipeutils.py b/meta/lib/oe/recipeutils.py
index 6c7adb5bdb..304989cfc5 100644
--- a/meta/lib/oe/recipeutils.py
+++ b/meta/lib/oe/recipeutils.py
@@ -255,7 +255,7 @@ def patch_recipe_file(fn, values, patch=False, relpath=''):
     changed, tolines = bb.utils.edit_metadata(fromlines, varlist, patch_recipe_varfunc, match_overrides=True)
 
     if remainingnames:
-        if tolines[-1].strip() != '':
+        if tolines and tolines[-1].strip() != '':
             tolines.append('\n')
         for k in remainingnames.keys():
             outputvalue(k, tolines)