read-cache.c: fix memory leaks caused by removed cache entries

When cache_entry structs are removed from index_state.cache, they are not
properly freed. Freeing those entries wasn't possible before because we
couldn't remove them from index_state.name_hash.

Now that we _do_ remove the entries from name_hash, we can also free them.
Add 'free(cache_entry)' to all call sites of name-hash.c::remove_name_hash
in read-cache.c (we could free() directly in remove_name_hash(), but
name-hash.c isn't concerned with cache_entry allocation at all).

Accessing a cache_entry after removing it from the index is now no longer
allowed, as the memory has been freed. The following functions need minor
fixes (typically by copying ce->name before use):
 - builtin/rm.c::cmd_rm
 - builtin/update-index.c::do_reupdate
 - read-cache.c::read_index_unmerged
 - resolve-undo.c::unmerge_index_entry_at

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/builtin/update-index.c b/builtin/update-index.c
index c8f0d5f47c..00313f373a 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -559,6 +559,7 @@ static int do_reupdate(int ac, const char **av,
 		const struct cache_entry *ce = active_cache[pos];
 		struct cache_entry *old = NULL;
 		int save_nr;
+		char *path;
 
 		if (ce_stage(ce) || !ce_path_match(ce, &pathspec))
 			continue;
@@ -575,7 +576,9 @@ static int do_reupdate(int ac, const char **av,
 		 * or worse yet 'allow_replace', active_nr may decrease.
 		 */
 		save_nr = active_nr;
-		update_one(ce->name);
+		path = xstrdup(ce->name);
+		update_one(path);
+		free(path);
 		if (save_nr != active_nr)
 			goto redo;
 	}