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)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.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 0e7abf833b..c77664f135 100644
--- a/meta/lib/oe/recipeutils.py
+++ b/meta/lib/oe/recipeutils.py
@@ -259,7 +259,7 @@ def patch_recipe_lines(fromlines, values, trailing_newline=True):
     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)