bug #1461855: make os.fdopen() add the O_APPEND flag if using "a" mode.

glibc, for example, does this already on its own, but it seems that
the solaris libc doesn't. This leads to Python code being able to over-
write file contents even though having specified "a" mode.
This commit is contained in:
Georg Brandl 2006-03-31 20:00:11 +00:00
parent dcdfd22bb4
commit 54a188aed8
1 changed files with 13 additions and 2 deletions

View File

@ -5768,9 +5768,20 @@ posix_fdopen(PyObject *self, PyObject *args)
"invalid file mode '%s'", mode);
return NULL;
}
Py_BEGIN_ALLOW_THREADS
fp = fdopen(fd, mode);
if (mode[0] == 'a') {
/* try to make sure the O_APPEND flag is set */
int flags;
flags = fcntl(fd, F_GETFL);
if (flags != -1)
fcntl(fd, F_SETFL, flags | O_APPEND);
fp = fdopen(fd, mode);
if (fp == NULL)
/* restore old mode if fdopen failed */
fcntl(fd, F_SETFL, flags);
} else {
fp = fdopen(fd, mode);
}
Py_END_ALLOW_THREADS
if (fp == NULL)
return posix_error();