Test of unsigned long vs. int64_t.

tests/run/type_inference.pyx

@@ -697,8 +697,13 @@ def int64_long_sum():
     cdef long x = 1
     cdef int32_t x32 = 2
     cdef int64_t x64 = 3
+    cdef unsigned long ux = 4
     assert typeof(x + x32) == typeof(x32 + x) == 'long', typeof(x + x32)
     assert typeof(x + x64) == typeof(x64 + x) == 'int64_t', typeof(x + x64)
+    # The correct answer here is either unsigned long or int64_t, depending on
+    # whether sizeof(long) == 64 or not.  Incorrect signedness is probably
+    # preferable to incorrect width.
+    assert typeof(ux + x64) == typeof(x64 + ux) == 'int64_t', typeof(ux + x64)
 
 cdef class InferInProperties:
     """