mode = 0;
        }
 
-       if (DIFF_OPT_TST(opt, RECURSIVE) && isdir) {
+       if (opt->flags.recursive && isdir) {
                recurse = 1;
-               emitthis = DIFF_OPT_TST(opt, TREE_IN_RECURSIVE);
+               emitthis = opt->flags.tree_in_recursive;
        }
 
        if (emitthis) {
                                                DIFF_STATUS_ADDED;
 
                        if (tpi_valid) {
-                               oid_i = tp[i].entry.oid;
+                               oid_i = &tp[i].entry.oid;
                                mode_i = tp[i].entry.mode;
                        }
                        else {
                        /* same rule as in emitthis */
                        int tpi_valid = tp && !(tp[i].entry.mode & S_IFXMIN_NEQ);
 
-                       parents_oid[i] = tpi_valid ? tp[i].entry.oid : NULL;
+                       parents_oid[i] = tpi_valid ? &tp[i].entry.oid : NULL;
                }
 
                strbuf_add(base, path, pathlen);
        enum interesting match;
 
        while (t->size) {
-               match = tree_entry_interesting(&t->entry, base, 0, &opt->pathspec);
+               match = tree_entry_interesting(opt->repo->index, &t->entry,
+                                              base, 0, &opt->pathspec);
                if (match) {
                        if (match == all_entries_not_interesting)
                                t->size = 0;
         *   diff_tree_oid(parent, commit) )
         */
        for (i = 0; i < nparent; ++i)
-               tptree[i] = fill_tree_descriptor(&tp[i],
-                               parents_oid[i] ? parents_oid[i]->hash : NULL);
-       ttree = fill_tree_descriptor(&t, oid ? oid->hash : NULL);
+               tptree[i] = fill_tree_descriptor(&tp[i], parents_oid[i]);
+       ttree = fill_tree_descriptor(&t, oid);
 
        /* Enable recursion indefinitely */
-       opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);
+       opt->pathspec.recursive = opt->flags.recursive;
 
        for (;;) {
                int imin, cmp;
                /* t = p[imin] */
                if (cmp == 0) {
                        /* are either pi > p[imin] or diff(t,pi) != ø ? */
-                       if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
+                       if (!opt->flags.find_copies_harder) {
                                for (i = 0; i < nparent; ++i) {
                                        /* p[i] > p[imin] */
                                        if (tp[i].entry.mode & S_IFXMIN_NEQ)
                                                continue;
 
                                        /* diff(t,pi) != ø */
-                                       if (oidcmp(t.entry.oid, tp[i].entry.oid) ||
+                                       if (!oideq(&t.entry.oid, &tp[i].entry.oid) ||
                                            (t.entry.mode != tp[i].entry.mode))
                                                continue;
 
                /* t > p[imin] */
                else {
                        /* ∀i pi=p[imin] -> D += "-p[imin]" */
-                       if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER)) {
+                       if (!opt->flags.find_copies_harder) {
                                for (i = 0; i < nparent; ++i)
                                        if (tp[i].entry.mode & S_IFXMIN_NEQ)
                                                goto skip_emit_tp;
         * free pre-allocated last element, if any
         * (see path_appendnew() for details about why)
         */
-       if (p->next) {
-               FREE_AND_NULL(p->next);
-       }
+       FREE_AND_NULL(p->next);
 
        return p;
 }
        choice = q->queue[0];
        q->nr = 0;
 
-       diff_setup(&diff_opts);
-       DIFF_OPT_SET(&diff_opts, RECURSIVE);
-       DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+       repo_diff_setup(opt->repo, &diff_opts);
+       diff_opts.flags.recursive = 1;
+       diff_opts.flags.find_copies_harder = 1;
        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
        diff_opts.single_follow = opt->pathspec.items[0].match;
        diff_opts.break_opt = opt->break_opt;
        strbuf_addstr(&base, base_str);
 
        retval = ll_diff_tree_oid(old_oid, new_oid, &base, opt);
-       if (!*base_str && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename())
+       if (!*base_str && opt->flags.follow_renames && diff_might_be_rename())
                try_to_follow_renames(old_oid, new_oid, &base, opt);
 
        strbuf_release(&base);