_emerge.Package.iuse.is_valid_flags should return a list of flags missing from IUSE

diff --git a/pym/_emerge/Package.py b/pym/_emerge/Package.py
index 93b86f10b6b6253c4278765f9f6b4518cd59991b..0eba4b65a1b9506e4bfe4eab6a6855ef9dcab873 100644 (file)
--- a/pym/_emerge/Package.py
+++ b/pym/_emerge/Package.py
@@ -214,11 +214,12 @@ class Package(Task):
                        """
                        if isinstance(flags, basestring):
                                flags = [flags]
+                       missing_iuse = []
                        for flag in flags:
                                if not flag in self.all and \
                                        self._iuse_implicit_regex.match(flag) is None:
-                                       return False
-                       return True
+                                       missing_iuse.append(flag)
+                       return missing_iuse
 
        def _get_hash_key(self):
                hash_key = getattr(self, "_hash_key", None)