* Copyright (c) 2006 Junio C Hamano
  */
 #include "cache.h"
+#include "color.h"
 #include "commit.h"
 #include "blob.h"
 #include "tag.h"
            !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
                return;
 
-       if (opt->reverse_diff) {
+       if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
                unsigned tmp;
                const unsigned char *tmp_u;
                const char *tmp_c;
                tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
                tmp_c = old_name; old_name = new_name; new_name = tmp_c;
        }
+
+       if (opt->prefix &&
+           (strncmp(old_name, opt->prefix, opt->prefix_length) ||
+            strncmp(new_name, opt->prefix, opt->prefix_length)))
+               return;
+
        one = alloc_filespec(old_name);
        two = alloc_filespec(new_name);
        fill_filespec(one, old_sha1, old_mode);
        fill_filespec(two, new_sha1, new_mode);
 
-       /* NEEDSWORK: shouldn't this part of diffopt??? */
        diff_queue(&diff_queued_diff, one, two);
 }
 
        return 0;
 }
 
-void add_head(struct rev_info *revs)
-{
-       unsigned char sha1[20];
-       struct object *obj;
-       if (get_sha1("HEAD", sha1))
-               return;
-       obj = parse_object(sha1);
-       if (!obj)
-               return;
-       add_pending_object(revs, obj, "HEAD");
-}
-
 static void refresh_index_quietly(void)
 {
        struct lock_file *lock_file;
        refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 
        if (active_cache_changed &&
-           !write_cache(fd, active_cache, active_nr) && !close(fd))
+           !write_cache(fd, active_cache, active_nr))
                commit_locked_index(lock_file);
 
        rollback_lock_file(lock_file);
        int ents = 0, blobs = 0, paths = 0;
        const char *path = NULL;
        struct blobinfo blob[2];
-       int nongit = 0;
+       int nongit;
        int result = 0;
 
        /*
 
        prefix = setup_git_directory_gently(&nongit);
        git_config(git_diff_ui_config);
+
+       if (diff_use_color_default == -1)
+               diff_use_color_default = git_use_color_default;
+
        init_revisions(&rev, prefix);
        rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 
                if (diff_setup_done(&rev.diffopt) < 0)
                        die("diff_setup_done failed");
        }
-       rev.diffopt.allow_external = 1;
-       rev.diffopt.recursive = 1;
+       if (rev.diffopt.prefix && nongit) {
+               rev.diffopt.prefix = NULL;
+               rev.diffopt.prefix_length = 0;
+       }
+       DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
+       DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 
-       /* If the user asked for our exit code then don't start a
+       /*
+        * If the user asked for our exit code then don't start a
         * pager or we would end up reporting its exit code instead.
         */
-       if (!rev.diffopt.exit_with_status)
+       if (!DIFF_OPT_TST(&rev.diffopt, EXIT_WITH_STATUS))
                setup_pager();
 
        /* Do we have --cached and not have a pending object, then
                        if (!strcmp(arg, "--"))
                                break;
                        else if (!strcmp(arg, "--cached")) {
-                               add_head(&rev);
+                               add_head_to_pending(&rev);
                                if (!rev.pending.nr)
                                        die("No HEAD commit to compare with (yet)");
                                break;
        else
                result = builtin_diff_combined(&rev, argc, argv,
                                             ent, ents);
-       if (rev.diffopt.exit_with_status)
-               result = rev.diffopt.has_changes;
-
+       result = diff_result_code(&rev.diffopt, result);
        if (1 < rev.diffopt.skip_stat_unmatch)
                refresh_index_quietly();
        return result;