Allow buffer_size=None, to avoid setting explicitly.

Author: Ben Cipollini

nibabel/gifti/tests/test_parse_gifti_fast.py

@@ -330,3 +330,9 @@ def test_parse_deprecated():
         warnings.filterwarnings('always', category=DeprecationWarning)
         assert_raises(ValueError, parse_gifti_file)
         assert_equal(len(w), 1)
+
+
+def test_parse_with_buffersize():
+    for buff_sz in [None, 1, 2**12]:
+        img2 = load(DATA_FILE2, buffer_size=buff_sz)
+        assert_equal(img2.darrays[0].data.shape, (143479, 1))

nibabel/xmlbasedimages.py

@@ -71,7 +71,8 @@ def _create_parser(self):
 
         parser = ParserCreate(encoding=self.encoding)  # from xml package
         parser.buffer_text = True
-        parser.buffer_size = self.buffer_size
+        if self.buffer_size is not None:
+            parser.buffer_size = self.buffer_size
         return parser
 
     def parse(self, string=None, fname=None, fptr=None):