log-tree: show_log: make commentary block delimiting reusable

diff --git a/builtin/log.c b/builtin/log.c
index 1020b784770edde3df46f972e2bb5e5ef675fe22..8078a43d14f014885cc4331cd516efbd5bff6524 100644 (file)
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1085,8 +1085,8 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
                show_diffstat(rev, origin, head);
 
        if (rev->idiff_oid1) {
-               fprintf_ln(rev->diffopt.file, "%s", _("Interdiff:"));
-               show_interdiff(rev);
+               fprintf_ln(rev->diffopt.file, "%s", rev->idiff_title);
+               show_interdiff(rev, 0);
        }
 }
 
@@ -1427,6 +1427,16 @@ static void print_bases(struct base_tree_info *bases, FILE *file)
        oidclr(&bases->base_commit);
 }
 
+static const char *diff_title(struct strbuf *sb, int reroll_count,
+                      const char *generic, const char *rerolled)
+{
+       if (reroll_count <= 0)
+               strbuf_addstr(sb, generic);
+       else /* RFC may be v0, so allow -v1 to diff against v0 */
+               strbuf_addf(sb, rerolled, reroll_count - 1);
+       return sb->buf;
+}
+
 int cmd_format_patch(int argc, const char **argv, const char *prefix)
 {
        struct commit *commit;
@@ -1455,6 +1465,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
        int show_progress = 0;
        struct progress *progress = NULL;
        struct oid_array idiff_prev = OID_ARRAY_INIT;
+       struct strbuf idiff_title = STRBUF_INIT;
 
        const struct option builtin_format_patch_options[] = {
                { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
@@ -1758,6 +1769,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
                        die(_("--interdiff requires --cover-letter"));
                rev.idiff_oid1 = &idiff_prev.oid[idiff_prev.nr - 1];
                rev.idiff_oid2 = get_commit_tree_oid(list[0]);
+               rev.idiff_title = diff_title(&idiff_title, reroll_count,
+                                            _("Interdiff:"),
+                                            _("Interdiff against v%d:"));
        }
 
        if (!signature) {
@@ -1880,6 +1894,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 
 done:
        oid_array_clear(&idiff_prev);
+       strbuf_release(&idiff_title);
        return 0;
 }