diff -r a32a3b79f5e8 Misc/ACKS
--- a/Misc/ACKS	Sun May 12 17:29:34 2013 +0300
+++ b/Misc/ACKS	Tue May 14 21:32:55 2013 +0300
@@ -693,6 +693,7 @@
 Dom Mitchell
 Florian Mladitsch
 Doug Moen
+Jaakko Moisio
 The Dragon De Monsyne
 Skip Montanaro
 Paul Moore
diff -r a32a3b79f5e8 Objects/fileobject.c
--- a/Objects/fileobject.c	Sun May 12 17:29:34 2013 +0300
+++ b/Objects/fileobject.c	Tue May 14 21:32:55 2013 +0300
@@ -1853,7 +1853,7 @@
     Py_XDECREF(encoded);
     if (f->f_binary)
         PyBuffer_Release(&pbuf);
-    if (n2 != n) {
+    if (n2 != n || errno != 0) {
         PyErr_SetFromErrno(PyExc_IOError);
         clearerr(f->f_fp);
         return NULL;