Fix conditional expressions involving references.

Formerly bad code involving unassigned reference temporaries was generated.

Cython/Compiler/ExprNodes.py

@@ -10800,6 +10800,8 @@ class CondExprNode(ExprNode):
     def analyse_result_type(self, env):
         self.type = PyrexTypes.independent_spanning_type(
             self.true_val.type, self.false_val.type)
+        if self.type.is_reference:
+            self.type = PyrexTypes.CFakeReferenceType(self.type.ref_base_type)
         if self.type.is_pyobject:
             self.result_ctype = py_object_type
         elif self.true_val.is_ephemeral() or self.false_val.is_ephemeral():

Cython/Compiler/PyrexTypes.py

@@ -4170,6 +4170,11 @@ def independent_spanning_type(type1, type2):
     # whereas "x = True or 2" must evaluate to a type that can hold
     # both a boolean value and an integer, so this function works
     # better.
+    if type1.is_reference ^ type2.is_reference:
+        if type1.is_reference:
+            type1 = type1.ref_base_type
+        else:
+            type2 = type2.ref_base_type
     if type1 == type2:
         return type1
     elif (type1 is c_bint_type or type2 is c_bint_type) and (type1.is_numeric and type2.is_numeric):