Fix inheriting when appending to variables.

diff --git a/pakfire/packages/lexer.py b/pakfire/packages/lexer.py
index 54572c470cdc8cf3faedd3147982238a63bc81d0..bb32300cb00d432c0e944f6048468b533a3aaa53 100644 (file)
--- a/pakfire/packages/lexer.py
+++ b/pakfire/packages/lexer.py
@@ -310,8 +310,10 @@ class Lexer(object):
 
                if o == "+":
                        prev = self.definitions.get(k, None)
+                       if prev is None and self.parent:
+                               prev = self.parent.definitions.get(k, None)
                        if prev:
-                               v = " ".join((prev, v))
+                               v = " ".join((prev or "", v))
 
                # Handle backslash.
                while v and v.endswith("\\"):