update-index: ensure full index

Before iterating over all cache entries, ensure that a sparse index is
expanded to a full index to avoid unexpected behavior.

Signed-off-by: Derrick Stolee <[email protected]>
Reviewed-by: Elijah Newren <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: derrickstolee

builtin/update-index.c

@@ -745,6 +745,8 @@ static int do_reupdate(int ac, const char **av,
 		 */
 		has_head = 0;
  redo:
+	/* TODO: audit for interaction with sparse-index. */
+	ensure_full_index(&the_index);
 	for (pos = 0; pos < active_nr; pos++) {
 		const struct cache_entry *ce = active_cache[pos];
 		struct cache_entry *old = NULL;