closes bpo-27805: Ignore ESPIPE in initializing seek of append-mode files. (GH-17112)

This change, which follows the behavior of C stdio's fdopen and Python 2's file object, allows pipes to be opened in append mode.
This commit is contained in:
Benjamin Peterson 2019-11-12 14:51:34 -08:00 committed by GitHub
parent d593881505
commit 74fa9f723f
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 33 additions and 10 deletions

View file

@ -4,6 +4,7 @@
#include "Python.h"
#include "pycore_object.h"
#include "structmember.h"
#include <stdbool.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
@ -75,7 +76,7 @@ _Py_IDENTIFIER(name);
#define PyFileIO_Check(op) (PyObject_TypeCheck((op), &PyFileIO_Type))
/* Forward declarations */
static PyObject* portable_lseek(fileio *self, PyObject *posobj, int whence);
static PyObject* portable_lseek(fileio *self, PyObject *posobj, int whence, bool suppress_pipe_error);
int
_PyFileIO_closed(PyObject *self)
@ -480,7 +481,7 @@ _io_FileIO___init___impl(fileio *self, PyObject *nameobj, const char *mode,
/* For consistent behaviour, we explicitly seek to the
end of file (otherwise, it might be done only on the
first write()). */
PyObject *pos = portable_lseek(self, NULL, 2);
PyObject *pos = portable_lseek(self, NULL, 2, true);
if (pos == NULL)
goto error;
Py_DECREF(pos);
@ -603,7 +604,7 @@ _io_FileIO_seekable_impl(fileio *self)
return err_closed();
if (self->seekable < 0) {
/* portable_lseek() sets the seekable attribute */
PyObject *pos = portable_lseek(self, NULL, SEEK_CUR);
PyObject *pos = portable_lseek(self, NULL, SEEK_CUR, false);
assert(self->seekable >= 0);
if (pos == NULL) {
PyErr_Clear();
@ -870,7 +871,7 @@ _io_FileIO_write_impl(fileio *self, Py_buffer *b)
/* Cribbed from posix_lseek() */
static PyObject *
portable_lseek(fileio *self, PyObject *posobj, int whence)
portable_lseek(fileio *self, PyObject *posobj, int whence, bool suppress_pipe_error)
{
Py_off_t pos, res;
int fd = self->fd;
@ -921,8 +922,13 @@ portable_lseek(fileio *self, PyObject *posobj, int whence)
self->seekable = (res >= 0);
}
if (res < 0)
return PyErr_SetFromErrno(PyExc_OSError);
if (res < 0) {
if (suppress_pipe_error && errno == ESPIPE) {
res = 0;
} else {
return PyErr_SetFromErrno(PyExc_OSError);
}
}
#if defined(HAVE_LARGEFILE_SUPPORT)
return PyLong_FromLongLong(res);
@ -955,7 +961,7 @@ _io_FileIO_seek_impl(fileio *self, PyObject *pos, int whence)
if (self->fd < 0)
return err_closed();
return portable_lseek(self, pos, whence);
return portable_lseek(self, pos, whence, false);
}
/*[clinic input]
@ -973,7 +979,7 @@ _io_FileIO_tell_impl(fileio *self)
if (self->fd < 0)
return err_closed();
return portable_lseek(self, NULL, 1);
return portable_lseek(self, NULL, 1, false);
}
#ifdef HAVE_FTRUNCATE
@ -1004,7 +1010,7 @@ _io_FileIO_truncate_impl(fileio *self, PyObject *posobj)
if (posobj == Py_None) {
/* Get the current position. */
posobj = portable_lseek(self, NULL, 1);
posobj = portable_lseek(self, NULL, 1, false);
if (posobj == NULL)
return NULL;
}