This fixes issue7900 by adding code that deals
with the fact that getgroups(2) might return
more that MAX_GROUPS on OSX.
See the issue (and python-dev archives) for the
gory details. Summarized: OSX behaves rather oddly
and Apple says this is intentional.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 65a0a5e..cb3075b 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -3995,17 +3995,49 @@
#define MAX_GROUPS 64
#endif
gid_t grouplist[MAX_GROUPS];
+
+ /* On MacOSX getgroups(2) can return more than MAX_GROUPS results
+ * This is a helper variable to store the intermediate result when
+ * that happens.
+ *
+ * To keep the code readable the OSX behaviour is unconditional,
+ * according to the POSIX spec this should be safe on all unix-y
+ * systems.
+ */
+ gid_t* alt_grouplist = grouplist;
int n;
n = getgroups(MAX_GROUPS, grouplist);
- if (n < 0)
- posix_error();
- else {
- result = PyList_New(n);
- if (result != NULL) {
+ if (n < 0) {
+ if (errno == EINVAL) {
+ n = getgroups(0, NULL);
+ if (n == -1) {
+ return posix_error();
+ }
+ if (n == 0) {
+ /* Avoid malloc(0) */
+ alt_grouplist = grouplist;
+ } else {
+ alt_grouplist = PyMem_Malloc(n * sizeof(gid_t));
+ if (alt_grouplist == NULL) {
+ errno = EINVAL;
+ return posix_error();
+ }
+ n = getgroups(n, alt_grouplist);
+ if (n == -1) {
+ PyMem_Free(alt_grouplist);
+ return posix_error();
+ }
+ }
+ } else {
+ return posix_error();
+ }
+ }
+ result = PyList_New(n);
+ if (result != NULL) {
int i;
for (i = 0; i < n; ++i) {
- PyObject *o = PyLong_FromLong((long)grouplist[i]);
+ PyObject *o = PyLong_FromLong((long)alt_grouplist[i]);
if (o == NULL) {
Py_DECREF(result);
result = NULL;
@@ -4013,7 +4045,10 @@
}
PyList_SET_ITEM(result, i, o);
}
- }
+ }
+
+ if (alt_grouplist != grouplist) {
+ PyMem_Free(alt_grouplist);
}
return result;