xcode_settings entries with list values override entries with the same key

pylib/gyp/xcodeproj_file.py

Index: pylib/gyp/xcodeproj_file.py
===================================================================
--- pylib/gyp/xcodeproj_file.py	(revision 1556)
+++ pylib/gyp/xcodeproj_file.py	(working copy)
@@ -1556,8 +1556,12 @@
     return self._properties['buildSettings'][key]
 
   def SetBuildSetting(self, key, value):
-    # TODO(mark): If a list, copy?
-    self._properties['buildSettings'][key] = value
+    if hasattr(value, '__iter__'):
+      if not key in self._properties['buildSettings']:
+        self._properties['buildSettings'][key] = []
+      self._properties['buildSettings'][key].extend(value)

[Sam Clegg, 2013/01/30 16:08:59]

nit: I think you can write these three lines as one using
the .setdefault() method on the dict.

Actually there is an existing method below called
AppendBuildSettings() that already does this (and should
probably use setdefault() itself).

+    else:
+      self._properties['buildSettings'][key] = value
 
   def AppendBuildSetting(self, key, value):
     if not key in self._properties['buildSettings']: