format-patch: extend --range-diff to accept revision range

diff --git a/builtin/log.c b/builtin/log.c
index 4b65673f12978d78b1819c410417278670a7ff20..fa54090b0264030be8a6626b5ddd35f9659185a4 100644 (file)
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1448,12 +1448,21 @@ static const char *diff_title(struct strbuf *sb, int reroll_count,
 static void infer_range_diff_ranges(struct strbuf *r1,
                                    struct strbuf *r2,
                                    const char *prev,
+                                   struct commit *origin,
                                    struct commit *head)
 {
        const char *head_oid = oid_to_hex(&head->object.oid);
 
-       strbuf_addf(r1, "%s..%s", head_oid, prev);
-       strbuf_addf(r2, "%s..%s", prev, head_oid);
+       if (!strstr(prev, "..")) {
+               strbuf_addf(r1, "%s..%s", head_oid, prev);
+               strbuf_addf(r2, "%s..%s", prev, head_oid);
+       } else if (!origin) {
+               die(_("failed to infer range-diff ranges"));
+       } else {
+               strbuf_addstr(r1, prev);
+               strbuf_addf(r2, "%s..%s",
+                           oid_to_hex(&origin->object.oid), head_oid);
+       }
 }
 
 int cmd_format_patch(int argc, const char **argv, const char *prefix)
@@ -1802,7 +1811,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
                if (!cover_letter)
                        die(_("--range-diff requires --cover-letter"));
 
-               infer_range_diff_ranges(&rdiff1, &rdiff2, rdiff_prev, list[0]);
+               infer_range_diff_ranges(&rdiff1, &rdiff2, rdiff_prev,
+                                       origin, list[0]);
                rev.rdiff1 = rdiff1.buf;
                rev.rdiff2 = rdiff2.buf;
                rev.creation_factor = RANGE_DIFF_CREATION_FACTOR_DEFAULT;