[Python-checkins] cpython (2.7): Issue #17976: Fixed potential problem with file.write() not detecting IO error

Tue Dec 17 13:40:53 CET 2013

http://hg.python.org/cpython/rev/33c27b76a4d0
changeset: 88019:33c27b76a4d0
branch: 2.7
parent: 88002:4de09cbd3b97
user: Serhiy Storchaka <storchaka at gmail.com>
date: Tue Dec 17 14:40:06 2013 +0200
summary:
 Issue #17976: Fixed potential problem with file.write() not detecting IO error
by inspecting the return value of fwrite(). Based on patches by Jaakko Moisio
and test by Victor Stinner.
files:
 Lib/test/test_file2k.py | 8 ++++++++
 Misc/ACKS | 1 +
 Misc/NEWS | 4 ++++
 Objects/fileobject.c | 6 +++++-
 4 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/Lib/test/test_file2k.py b/Lib/test/test_file2k.py
--- a/Lib/test/test_file2k.py
+++ b/Lib/test/test_file2k.py
@@ -415,6 +415,14 @@
 finally:
 os.unlink(TESTFN)
 
+ @unittest.skipUnless(os.name == 'posix', 'test requires a posix system.')
+ def test_write_full(self):
+ # Issue #17976
+ with open('/dev/full', 'w', 1) as f:
+ with self.assertRaises(IOError):
+ f.write('hello')
+ f.write('\n')
+
 class FileSubclassTests(unittest.TestCase):
 
 def testExit(self):
diff --git a/Misc/ACKS b/Misc/ACKS
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -710,6 +710,7 @@
 Dom Mitchell
 Florian Mladitsch
 Doug Moen
+Jaakko Moisio
 The Dragon De Monsyne
 Skip Montanaro
 Paul Moore
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,10 @@
 Core and Builtins
 -----------------
 
+- Issue #17976: Fixed potential problem with file.write() not detecting IO error
+ by inspecting the return value of fwrite(). Based on patches by Jaakko Moisio
+ and Victor Stinner.
+
 - Issue #14432: Generator now clears the borrowed reference to the thread
 state. Fix a crash when a generator is created in a C thread that is
 destroyed while the generator is still used. The issue was that a generator
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -1804,6 +1804,7 @@
 const char *s;
 Py_ssize_t n, n2;
 PyObject *encoded = NULL;
+ int err = 0;
 
 if (f->f_fp == NULL)
 return err_closed();
@@ -1849,11 +1850,14 @@
 FILE_BEGIN_ALLOW_THREADS(f)
 errno = 0;
 n2 = fwrite(s, 1, n, f->f_fp);
+ if (n2 != n || ferror(f->f_fp))
+ err = errno;
 FILE_END_ALLOW_THREADS(f)
 Py_XDECREF(encoded);
 if (f->f_binary)
 PyBuffer_Release(&pbuf);
- if (n2 != n) {
+ if (err) {
+ errno = err;
 PyErr_SetFromErrno(PyExc_IOError);
 clearerr(f->f_fp);
 return NULL;
-- 
Repository URL: http://hg.python.org/cpython
