When passed an empty list, objects_array_remove_duplicates() corrupts it
by changing the number of entries from 0 to 1.
The problem lies in the condition of its main loop:
for (ref = 0; ref < array->nr - 1; ref++) {
The loop body manipulates the supplied object array. In the case of an
empty array, it should not be doing anything at all. But array->nr is an
unsigned quantity, so the code enters the loop, in particular increasing
array->nr. Fix this by comparing (ref + 1 < array->nr) instead.
This bug can be triggered by git bundle --stdin:
$ echo HEAD | git bundle create some.bundle --stdin’
Segmentation fault (core dumped)
The list of commits to bundle appears to be empty because of another bug:
by the time the revision-walking machinery gets to look at it, standard
input has already been consumed by rev-list, so this function gets an
empty list of revisions.
After this patch, git bundle --stdin still does not work; it just doesn’t
segfault any more.
Reported-by: Joey Hess <joey@kitenet.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
void object_array_remove_duplicates(struct object_array *array)
{
- int ref, src, dst;
+ unsigned int ref, src, dst;
struct object_array_entry *objects = array->objects;
- for (ref = 0; ref < array->nr - 1; ref++) {
+ for (ref = 0; ref + 1 < array->nr; ref++) {
for (src = ref + 1, dst = src;
src < array->nr;
src++) {