[pypy-svn] pypy default: Fix test_overseek.

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: 
Changeset: r41471:77ff14cd6f37
Date: 2011-01-30 00:24 -0500
http://bitbucket.org/pypy/pypy/changeset/77ff14cd6f37/

Log:	Fix test_overseek.

diff --git a/pypy/module/_io/test/test_stringio.py b/pypy/module/_io/test/test_stringio.py
--- a/pypy/module/_io/test/test_stringio.py
+++ b/pypy/module/_io/test/test_stringio.py
@@ -58,6 +58,23 @@
         sio.close()
         raises(ValueError, sio.seek, 0)
 
+    def test_overseek(self):
+        import io
+
+        s = u"1234567890"
+        sio = io.StringIO(s)
+
+        res = sio.seek(11)
+        assert res == 11
+        res = sio.read()
+        assert res == u""
+        assert sio.tell() == 11
+        assert sio.getvalue() == s
+        sio.write(u"")
+        assert sio.getvalue() == s
+        sio.write(s)
+        assert sio.getvalue() == s + u"\0" + s
+
     def test_tell(self):
         import io
 

diff --git a/pypy/module/_io/interp_stringio.py b/pypy/module/_io/interp_stringio.py
--- a/pypy/module/_io/interp_stringio.py
+++ b/pypy/module/_io/interp_stringio.py
@@ -67,6 +67,8 @@
         size = convert_size(space, w_size)
         start = self.pos
         available = len(self.buf) - start
+        if available <= 0:
+            return space.wrap(u"")
         if size >= 0 and size <= available:
             end = start + size
         else: