submodule: add a helper to check if it is safe to write to .gitmodules

diff --git a/builtin/range-diff.c b/builtin/range-diff.c
index 3b06ed9449a39168aa606994e6e2cf28fcd22fee..0aa9bed41f35bf99784acd4abab52df415c5fb00 100644 (file)
--- a/builtin/range-diff.c
+++ b/builtin/range-diff.c
@@ -11,22 +11,35 @@ N_("git range-diff [<options>] <base> <old-tip> <new-tip>"),
 NULL
 };
 
+static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
+{
+       return data;
+}
+
 int cmd_range_diff(int argc, const char **argv, const char *prefix)
 {
        int creation_factor = 60;
        struct diff_options diffopt = { NULL };
+       int simple_color = -1;
        struct option options[] = {
                OPT_INTEGER(0, "creation-factor", &creation_factor,
                            N_("Percentage by which creation is weighted")),
+               OPT_BOOL(0, "no-dual-color", &simple_color,
+                           N_("use simple diff colors")),
                OPT_END()
        };
        int i, j, res = 0;
+       struct strbuf four_spaces = STRBUF_INIT;
        struct strbuf range1 = STRBUF_INIT, range2 = STRBUF_INIT;
 
        git_config(git_diff_ui_config, NULL);
 
        diff_setup(&diffopt);
        diffopt.output_format = DIFF_FORMAT_PATCH;
+       diffopt.flags.suppress_diff_headers = 1;
+       diffopt.output_prefix = output_prefix_cb;
+       strbuf_addstr(&four_spaces, "    ");
+       diffopt.output_prefix_data = &four_spaces;
 
        argc = parse_options(argc, argv, NULL, options,
                             builtin_range_diff_usage, PARSE_OPT_KEEP_UNKNOWN |
@@ -50,6 +63,13 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
                             options + ARRAY_SIZE(options) - 1, /* OPT_END */
                             builtin_range_diff_usage, 0);
 
+       if (simple_color < 1) {
+               if (!simple_color)
+                       /* force color when --dual-color was used */
+                       diffopt.use_color = 1;
+               diffopt.flags.dual_color_diffed_diffs = 1;
+       }
+
        if (argc == 2) {
                if (!strstr(argv[0], ".."))
                        die(_("no .. in range: '%s'"), argv[0]);
@@ -90,6 +110,7 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
 
        strbuf_release(&range1);
        strbuf_release(&range2);
+       strbuf_release(&four_spaces);
 
        return res;
 }