Transfer some fixes from the _fused_dispatch branch

Cython/Compiler/Nodes.py

@@ -2584,7 +2584,7 @@ def __pyx_fused_cpdef(signatures, args, kwargs):
 
     candidates = []
     for sig in signatures:
-        match_found = True
+        match_found = filter(None, dest_sig)
         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

@@ -781,8 +781,11 @@ class BufferType(BaseType):
         return "<BufferType %r>" % self.base
 
     def __str__(self):
-        cast_str = ', cast=True' if self.cast else ''
-        return "%s[%s, ndim=%d%s]" % (self.base, self.dtype, self.ndim,
+        if self.cast:
+            cast_str = ',cast=True'
+        else:
+            cast_str = ''
+        return "%s[%s,ndim=%d%s]" % (self.base, self.dtype, self.ndim,
                                       cast_str)
 
 class PyObjectType(PyrexType):