Merged revisions 76805 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r76805 | benjamin.peterson | 2009-12-13 13:19:07 -0600 (Sun, 13 Dec 2009) | 7 lines

  accept None as the same as having passed no argument in file types #7349

  This is for consistency with imitation file objects like StringIO and BytesIO.

  This commit also adds a few tests, where they were lacking for concerned
  methods.
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diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 438848b..37ddaeb 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -599,7 +599,7 @@
 	if (!self->readable)
 		return err_mode("reading");
 
-	if (!PyArg_ParseTuple(args, "|n", &size))
+	if (!PyArg_ParseTuple(args, "|O&", &_PyIO_ConvertSsize_t, &size))
 		return NULL;
 
         if (size < 0) {