Fix BufferType's assignable_from & some tests

Cython/Compiler/Nodes.py

@@ -2578,7 +2578,7 @@ def __pyx_fused_cpdef(signatures, args, kwargs):
 
     candidates = []
     for sig in signatures:
-        match_found = filter(None, dest_sig)
+        match_found = [x for x in dest_sig if x]
         for src_type, dst_type in zip(sig.strip('()').split(', '), dest_sig):
             if dst_type is not None and match_found:
                 match_found = src_type == dst_type

Cython/Compiler/PyrexTypes.py

@@ -791,14 +791,21 @@ class BufferType(BaseType):
                                       cast_str)
 
     def assignable_from(self, other_type):
-        return self.same_as(other_type) or other_type.is_pyobject
+        if other_type.is_buffer:
+            return (self.same_as(other_type, compare_base=False) and
+                    self.base.assignable_from(other_type.base))
 
-    def same_as(self, other_type):
-        return (other_type.is_buffer and
-                self.dtype.same_as(other_type.dtype) and
+        return self.base.assignable_from(other_type)
+
+    def same_as(self, other_type, compare_base=True):
+        if not other_type.is_buffer:
+            return other_type.same_as(self.base)
+
+        return (self.dtype.same_as(other_type.dtype) and
                 self.ndim == other_type.ndim and
                 self.mode == other_type.mode and
-                self.cast == other_type.cast) or self.base.same_as(other_type)
+                self.cast == other_type.cast and
+                (not compare_base or self.base.same_as(other_type.base)))
 
 
 class PyObjectType(PyrexType):

tests/run/numpy_test.pyx

@@ -528,7 +528,7 @@ cdef fused fused_external:
 def test_fused_external(np.ndarray[fused_external, ndim=1] a):
     """
     >>> import cython
-    >>> print sorted(test_fused_external.__signatures__)
+    >>> sorted(test_fused_external.__signatures__)
     ['float32_t', 'float64_t', 'int32_t', 'int64_t']
 
     >>> test_fused_external["float64_t"](double_array)
@@ -539,10 +539,7 @@ def test_fused_external(np.ndarray[fused_external, ndim=1] a):
 
     >>> test_fused_external(np.arange(100)) # fix in next release
     Traceback (most recent call last):
-      File "/Users/mark/source/py/osx/lib/python2.7/doctest.py", line 1248, in __run
-        compileflags, 1) in test.globs
-      File "<doctest numpy_test.__test__.test_fused_external (line 525)[5]>", line 1, in <module>
-      File "numpy_test.pyx", line 525, in numpy_test.__pyx_fused_cpdef (numpy_test.cpp:10264)
+        ...
     TypeError: No matching signature found
     """
     print a.dtype
@@ -554,6 +551,7 @@ cdef fused fused_buffers:
 def test_fused_buffers(fused_buffers arg):
     """
     >>> sorted(test_fused_buffers.__signatures__)
+    ['int64_t[::1]', 'ndarray[int32_t,ndim=1]']
     """
 
 cpdef _fused_cpdef_buffers(np.ndarray[fused_external] a):
@@ -562,6 +560,8 @@ cpdef _fused_cpdef_buffers(np.ndarray[fused_external] a):
 def test_fused_cpdef_buffers():
     """
     >>> test_fused_cpdef_buffers()
+    int32
+    int32
     """
     _fused_cpdef_buffers[np.int32_t](int32_array)