tree-diff: don't access hash of NULL object_id pointer

diff --git a/builtin/merge.c b/builtin/merge.c
index 703827f00668ca0df807f35e300f0927d00075cd..afaed6a2c2fa4d426e440b2bdcc7bb0461253449 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -415,7 +415,7 @@ static void finish(struct commit *head_commit,
                        DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
                opts.detect_rename = DIFF_DETECT_RENAME;
                diff_setup_done(&opts);
-               diff_tree_sha1(head->hash, new_head->hash, "", &opts);
+               diff_tree_oid(head, new_head, "", &opts);
                diffcore_std(&opts);
                diff_flush(&opts);
        }
@@ -605,13 +605,13 @@ static int read_tree_trivial(struct object_id *common, struct object_id *head,
        opts.verbose_update = 1;
        opts.trivial_merges_only = 1;
        opts.merge = 1;
-       trees[nr_trees] = parse_tree_indirect(common->hash);
+       trees[nr_trees] = parse_tree_indirect(common);
        if (!trees[nr_trees++])
                return -1;
-       trees[nr_trees] = parse_tree_indirect(head->hash);
+       trees[nr_trees] = parse_tree_indirect(head);
        if (!trees[nr_trees++])
                return -1;
-       trees[nr_trees] = parse_tree_indirect(one->hash);
+       trees[nr_trees] = parse_tree_indirect(one);
        if (!trees[nr_trees++])
                return -1;
        opts.fn = threeway_merge;
@@ -1123,7 +1123,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
        if (!branch || is_null_oid(&head_oid))
                head_commit = NULL;
        else
-               head_commit = lookup_commit_or_die(head_oid.hash, "HEAD");
+               head_commit = lookup_commit_or_die(&head_oid, "HEAD");
 
        init_diff_ui_defaults();
        git_config(git_merge_config, NULL);
@@ -1372,8 +1372,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
                        goto done;
                }
 
-               if (checkout_fast_forward(head_commit->object.oid.hash,
-                                         commit->object.oid.hash,
+               if (checkout_fast_forward(&head_commit->object.oid,
+                                         &commit->object.oid,
                                          overwrite_ignore)) {
                        ret = 1;
                        goto done;