Fixes a bug with unanalysed ResultRefNodes.

This fixes #1523.

Cython/Compiler/UtilNodes.py

@@ -149,6 +149,7 @@ class ResultRefNode(AtomicExprNode):
 
     def analyse_types(self, env):
         if self.expression is not None:
+            self.expression = self.expression.analyse_types(env)
             self.type = self.expression.type
         return self
 

tests/run/unpack.pyx

@@ -393,3 +393,13 @@ def unpack_literal_none_to_exttype():
     cdef ExtType a,b,c,d
     a, b = c, d = None, None
     return a,b,c,d
+
+
+# Github issue #1523
+def test_unpack_resultref():
+    """
+    >>> test_unpack_resultref()
+    ((1, set([])), 1, set([]))
+    """
+    a = b, c = 1, set()
+    return a, b, c