tree-walk: copy object ID before use

In a future commit, the pointer returned by tree_entry_extract will
point into the struct tree_desc, causing its lifetime to be bound to
that of the struct tree_desc itself.  To ensure this code path keeps
working, copy the object_id into a local variable so that it lives long
enough.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/tree-walk.c b/tree-walk.c
index 79bafbd1a23c4a9e20ec623c084778904c534be7..1e040fc20e09f3ff93b78f9f0f90a81f9a154827 100644 (file)
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -498,10 +498,10 @@ static int find_tree_entry(struct tree_desc *t, const char *name, struct object_
        int namelen = strlen(name);
        while (t->size) {
                const char *entry;
-               const struct object_id *oid;
+               struct object_id oid;
                int entrylen, cmp;
 
-               oid = tree_entry_extract(t, &entry, mode);
+               oidcpy(&oid, tree_entry_extract(t, &entry, mode));
                entrylen = tree_entry_len(&t->entry);
                update_tree_entry(t);
                if (entrylen > namelen)
@@ -512,7 +512,7 @@ static int find_tree_entry(struct tree_desc *t, const char *name, struct object_
                if (cmp < 0)
                        break;
                if (entrylen == namelen) {
-                       oidcpy(result, oid);
+                       oidcpy(result, &oid);
                        return 0;
                }
                if (name[entrylen] != '/')
@@ -520,10 +520,10 @@ static int find_tree_entry(struct tree_desc *t, const char *name, struct object_
                if (!S_ISDIR(*mode))
                        break;
                if (++entrylen == namelen) {
-                       oidcpy(result, oid);
+                       oidcpy(result, &oid);
                        return 0;
                }
-               return get_tree_entry(oid, name + entrylen, result, mode);
+               return get_tree_entry(&oid, name + entrylen, result, mode);
        }
        return -1;
 }