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

When submitting a revised a patch series, the --range-diff option embeds
a range-diff in the cover letter showing changes since the previous
version of the patch series. The argument to --range-diff is a simple
revision naming the tip of the previous series, which works fine if the
previous and current versions of the patch series share a common base.

However, it fails if the revision ranges of the old and new versions of
the series are disjoint. To address this shortcoming, extend
--range-diff to also accept an explicit revision range for the previous
series. For example:

git format-patch --cover-letter --range-diff=v1~3..v1 -3 v2

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index e7f404be3d0487a0749e8fb628ad2a8c08bbc51b..425145f536f4a45d2fce146e4a384e2ec3eb6851 100644 (file)
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -243,10 +243,12 @@ feeding the result to `git send-email`.
        As a reviewer aid, insert a range-diff (see linkgit:git-range-diff[1])
        into the cover letter showing the differences between the previous
        version of the patch series and the series currently being formatted.
-       `previous` is a single revision naming the tip of the previous
-       series which shares a common base with the series being formatted (for
+       `previous` can be a single revision naming the tip of the previous
+       series if it shares a common base with the series being formatted (for
        example `git format-patch --cover-letter --range-diff=feature/v1 -3
-       feature/v2`).
+       feature/v2`), or a revision range if the two versions of the series are
+       disjoint (for example `git format-patch --cover-letter
+       --range-diff=feature/v1~3..feature/v1 -3 feature/v2`).
 
 --notes[=<ref>]::
        Append the notes (see linkgit:git-notes[1]) for the commit

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;

diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index dd854b6ebc34623afa61486b8993bd31a0a8c070..3d7a2d8a4d8191f93a70b2e3d4878537cd2c5564 100755 (executable)
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -142,7 +142,7 @@ test_expect_success 'changed message' '
        test_cmp expected actual
 '
 
-for prev in topic
+for prev in topic master..topic
 do
        test_expect_success "format-patch --range-diff=$prev" '
                git format-patch --stdout --cover-letter --range-diff=$prev \