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, 6 insertions, 2 deletions

diff --git a/read-cache.c b/read-cache.c
index 00af9addd9..3f735f3c8e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -47,6 +47,7 @@ static void replace_index_entry(struct index_state *istate, int nr, struct cache
 	struct cache_entry *old = istate->cache[nr];
 
 	remove_name_hash(istate, old);
+	free(old);
 	set_index_entry(istate, nr, ce);
 	istate->cache_changed = 1;
 }
@@ -478,6 +479,7 @@ int remove_index_entry_at(struct index_state *istate, int pos)
 
 	record_resolve_undo(istate, ce);
 	remove_name_hash(istate, ce);
+	free(ce);
 	istate->cache_changed = 1;
 	istate->cache_nr--;
 	if (pos >= istate->cache_nr)
@@ -499,8 +501,10 @@ void remove_marked_cache_entries(struct index_state *istate)
 	unsigned int i, j;
 
 	for (i = j = 0; i < istate->cache_nr; i++) {
-		if (ce_array[i]->ce_flags & CE_REMOVE)
+		if (ce_array[i]->ce_flags & CE_REMOVE) {
 			remove_name_hash(istate, ce_array[i]);
+			free(ce_array[i]);
+		}
 		else
 			ce_array[j++] = ce_array[i];
 	}
@@ -1894,7 +1898,7 @@ int read_index_unmerged(struct index_state *istate)
 		new_ce->ce_mode = ce->ce_mode;
 		if (add_index_entry(istate, new_ce, 0))
 			return error("%s: cannot drop to stage #0",
-				     ce->name);
+				     new_ce->name);
 		i = index_name_pos(istate, new_ce->name, len);
 	}
 	return unmerged;