[PATCH] ref-filter: fix memory leak in `free_array_item()`

[Martin Ågren]

We treat the `value` pointer as a pointer to a struct and free its `s`
field. But `value` is in fact an array of structs. As a result, we only
free the first `s` out of `used_atom_cnt`-many and leak the rest. Make
sure we free all items in `value`.

In the caller, `ref_array_clear()`, this means we need to be careful not
to zero `used_atom_cnt` until after we've called `free_array_item()`. We
could move just a single line, but let's keep related things close
together instead, by first handling `array`, then `used_atom`.

Signed-off-by: Martin Ågren <martin.ag...@gmail.com>
---
 ref-filter.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/ref-filter.c b/ref-filter.c
index 791f0648a6..1c1a2af880 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2105,7 +2105,9 @@ static void free_array_item(struct ref_array_item *item)
 {
        free((char *)item->symref);
        if (item->value) {
-               free((char *)item->value->s);
+               int i;
+               for (i = 0; i < used_atom_cnt; i++)
+                       free((char *)item->value[i].s);
                free(item->value);
        }
        free(item);
@@ -2116,14 +2118,16 @@ void ref_array_clear(struct ref_array *array)
 {
        int i;
 
-       for (i = 0; i < used_atom_cnt; i++)
-               free((char *)used_atom[i].name);
-       FREE_AND_NULL(used_atom);
-       used_atom_cnt = 0;
        for (i = 0; i < array->nr; i++)
                free_array_item(array->items[i]);
        FREE_AND_NULL(array->items);
        array->nr = array->alloc = 0;
+
+       for (i = 0; i < used_atom_cnt; i++)
+               free((char *)used_atom[i].name);
+       FREE_AND_NULL(used_atom);
+       used_atom_cnt = 0;
+
        if (ref_to_worktree_map.worktrees) {
                hashmap_free(&(ref_to_worktree_map.map), 1);
                free_worktrees(ref_to_worktree_map.worktrees);
-- 
2.22.0.428.g6d5b264208