Issue #7865: The close() method of :mod:`io` objects should not swallow
exceptions raised by the implicit flush(). Also ensure that calling
close() several times is supported. Patch by Pascal Chambon.
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index 1343f1b..bdffb12 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -327,6 +327,7 @@
This is not implemented for read-only and non-blocking streams.
"""
+ self._checkClosed()
# XXX Should this return the number of bytes written???
__closed = False
@@ -337,10 +338,7 @@
This method has no effect if the file is already closed.
"""
if not self.__closed:
- try:
- self.flush()
- except IOError:
- pass # If flush() fails, just give up
+ self.flush()
self.__closed = True
def __del__(self):
@@ -709,14 +707,13 @@
### Flush and close ###
def flush(self):
+ if self.closed:
+ raise ValueError("flush of closed file")
self.raw.flush()
def close(self):
- if not self.closed and self.raw is not None:
- try:
- self.flush()
- except IOError:
- pass # If flush() fails, just give up
+ if self.raw is not None and not self.closed:
+ self.flush()
self.raw.close()
def detach(self):
@@ -1531,11 +1528,8 @@
self._telling = self._seekable
def close(self):
- if self.buffer is not None:
- try:
- self.flush()
- except IOError:
- pass # If flush() fails, just give up
+ if self.buffer is not None and not self.closed:
+ self.flush()
self.buffer.close()
@property
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index b3feb1b..2874d79 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -541,6 +541,20 @@
with self.open(zero, "r") as f:
self.assertRaises(OverflowError, f.read)
+ def test_flush_error_on_close(self):
+ f = self.open(support.TESTFN, "wb", buffering=0)
+ def bad_flush():
+ raise IOError()
+ f.flush = bad_flush
+ self.assertRaises(IOError, f.close) # exception not swallowed
+
+ def test_multi_close(self):
+ f = self.open(support.TESTFN, "wb", buffering=0)
+ f.close()
+ f.close()
+ f.close()
+ self.assertRaises(ValueError, f.flush)
+
class CIOTest(IOTest):
pass
@@ -642,6 +656,22 @@
raw.name = b"dummy"
self.assertEqual(repr(b), "<%s name='dummy'>" % clsname)
+ def test_flush_error_on_close(self):
+ raw = self.MockRawIO()
+ def bad_flush():
+ raise IOError()
+ raw.flush = bad_flush
+ b = self.tp(raw)
+ self.assertRaises(IOError, b.close) # exception not swallowed
+
+ def test_multi_close(self):
+ raw = self.MockRawIO()
+ b = self.tp(raw)
+ b.close()
+ b.close()
+ b.close()
+ self.assertRaises(ValueError, b.flush)
+
class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
read_mode = "rb"
@@ -2117,6 +2147,20 @@
for n in range(20):
self.assertEquals(content.count("Thread%03d\n" % n), 1)
+ def test_flush_error_on_close(self):
+ txt = self.TextIOWrapper(self.BytesIO(self.testdata), encoding="ascii")
+ def bad_flush():
+ raise IOError()
+ txt.flush = bad_flush
+ self.assertRaises(IOError, txt.close) # exception not swallowed
+
+ def test_multi_close(self):
+ txt = self.TextIOWrapper(self.BytesIO(self.testdata), encoding="ascii")
+ txt.close()
+ txt.close()
+ txt.close()
+ self.assertRaises(ValueError, txt.flush)
+
class CTextIOWrapperTest(TextIOWrapperTest):
def test_initialization(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index e024d60..12e13e9 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -31,6 +31,10 @@
Library
-------
+- Issue #7865: The close() method of :mod:`io` objects should not swallow
+ exceptions raised by the implicit flush(). Also ensure that calling
+ close() several times is supported. Patch by Pascal Chambon.
+
- Issue #8576: logging updated to remove usage of find_unused_port().
- Issue #4687: Fix accuracy of garbage collection runtimes displayed with
diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index ba937ed..feee9be 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -440,11 +440,7 @@
res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
ENTER_BUFFERED(self)
if (res == NULL) {
- /* If flush() fails, just give up */
- if (PyErr_ExceptionMatches(PyExc_IOError))
- PyErr_Clear();
- else
- goto end;
+ goto end;
}
Py_XDECREF(res);
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index 25ff247..a294332 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -169,6 +169,7 @@
static PyObject *
bytesio_flush(bytesio *self)
{
+ CHECK_CLOSED(self);
Py_RETURN_NONE;
}
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 3344847..3530562 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -183,11 +183,7 @@
res = PyObject_CallMethodObjArgs(self, _PyIO_str_flush, NULL);
PyObject_SetAttrString(self, "__IOBase_closed", Py_True);
if (res == NULL) {
- /* If flush() fails, just give up */
- if (PyErr_ExceptionMatches(PyExc_IOError))
- PyErr_Clear();
- else
- return NULL;
+ return NULL;
}
Py_XDECREF(res);
Py_RETURN_NONE;
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 90a4c09..c5d7b85 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -2405,16 +2405,30 @@
textiowrapper_close(textio *self, PyObject *args)
{
PyObject *res;
+ int r;
CHECK_INITIALIZED(self);
- res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
- if (res == NULL) {
- /* If flush() fails, just give up */
- PyErr_Clear();
- }
- else
- Py_DECREF(res);
- return PyObject_CallMethod(self->buffer, "close", NULL);
+ res = textiowrapper_closed_get(self, NULL);
+ if (res == NULL)
+ return NULL;
+ r = PyObject_IsTrue(res);
+ Py_DECREF(res);
+ if (r < 0)
+ return NULL;
+
+ if (r > 0) {
+ Py_RETURN_NONE; /* stream already closed */
+ }
+ else {
+ res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
+ if (res == NULL) {
+ return NULL;
+ }
+ else
+ Py_DECREF(res);
+
+ return PyObject_CallMethod(self->buffer, "close", NULL);
+ }
}
static PyObject *