[pypy-commit] pypy default: another test and fix for BytesIO.truncate()

[bdkearns]

Author: Brian Kearns <bdkearns at gmail.com>
Branch: 
Changeset: r63265:7c83049dafd8
Date: 2013-04-12 02:49 -0400
http://bitbucket.org/pypy/pypy/changeset/7c83049dafd8/

Log:	another test and fix for BytesIO.truncate()

diff --git a/pypy/module/_io/interp_bytesio.py b/pypy/module/_io/interp_bytesio.py
--- a/pypy/module/_io/interp_bytesio.py
+++ b/pypy/module/_io/interp_bytesio.py
@@ -62,8 +62,9 @@
     def truncate_w(self, space, w_size=None):
         self._check_closed(space)
 
+        pos = self.tell()
         if space.is_none(w_size):
-            size = self.tell()
+            size = pos
         else:
             size = space.r_longlong_w(w_size)
 
@@ -72,6 +73,7 @@
                 "negative size value"))
 
         self.truncate(size)
+        self.seek(pos)
         return space.wrap(size)
 
     def getvalue_w(self, space):
diff --git a/pypy/module/_io/test/test_bytesio.py b/pypy/module/_io/test/test_bytesio.py
--- a/pypy/module/_io/test/test_bytesio.py
+++ b/pypy/module/_io/test/test_bytesio.py
@@ -48,7 +48,12 @@
 
     def test_truncate(self):
         import _io
-        f = _io.BytesIO("hello")
+        f = _io.BytesIO()
+        f.write("hello")
+        assert f.truncate(0) == 0
+        assert f.tell() == 5
+        f.seek(0)
+        f.write("hello")
         f.seek(3)
         assert f.truncate() == 3
         assert f.getvalue() == "hel"