When submitting a revised version of a patch series, it can be helpful
(to reviewers) to include a summary of changes since the previous
attempt in the form of an interdiff or range-diff, however, doing so
involves manually copy/pasting the diff into the cover letter.
Add a --range-diff option to automate this process for range-diffs. The
argument to --range-diff specifies the tip of the previous attempt
against which to generate the range-diff. For example:
git format-patch --cover-letter --range-diff=v1 -3 v2
(At this early stage, the previous attempt and the patch series being
formatted must share a common base, however, a subsequent enhancement
will make it possible to specify an explicit revision range for the
previous attempt.)
Signed-off-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx>
---
Documentation/git-format-patch.txt | 10 ++++++
builtin/log.c | 55 ++++++++++++++++++++++++++++--
t/t7910-branch-diff.sh | 15 ++++++++
3 files changed, 77 insertions(+), 3 deletions(-)
diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 6cbe462a77..f4c70e6b64 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -23,6 +23,7 @@ SYNOPSIS
[(--reroll-count|-v) <n>]
[--to=<email>] [--cc=<email>]
[--[no-]cover-letter] [--quiet] [--notes[=<ref>]]
+ [--range-diff=<previous>]
[--progress]
[<common diff options>]
[ <since> | <revision range> ]
@@ -228,6 +229,15 @@ feeding the result to `git send-email`.
containing the branch description, shortlog and the overall diffstat. You can
fill in a description in the file before sending it out.
+--range-diff=<previous>::
+ As a reviewer aid, insert a range-diff (see linkgit:git-branch-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
+ example `git format-patch --cover-letter --range-diff=feature/v1 -3
+ feature/v2`).
+
--notes[=<ref>]::
Append the notes (see linkgit:git-notes[1]) for the commit
after the three-dash line.
diff --git a/builtin/log.c b/builtin/log.c
index e01a256c11..460c31a293 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -28,6 +28,7 @@
#include "mailmap.h"
#include "gpg-interface.h"
#include "progress.h"
+#include "run-command.h"
#define MAIL_DEFAULT_WRAP 72
@@ -992,6 +993,25 @@ static char *find_branch_name(struct rev_info *rev)
return branch;
}
+static void infer_diff_ranges(struct argv_array *args,
+ const char *prev,
+ struct commit *head)
+{
+ argv_array_pushf(args, "%s...%s", prev,
+ oid_to_hex(&head->object.oid));
+}
+
+static int get_range_diff(struct strbuf *sb,
+ const struct argv_array *ranges)
+{
+ struct child_process cp = CHILD_PROCESS_INIT;
+
+ cp.git_cmd = 1;
+ argv_array_pushl(&cp.args, "branch-diff", "--no-color", NULL);
+ argv_array_pushv(&cp.args, ranges->argv);
+ return capture_command(&cp, sb, 0);
+}
+
static void emit_diffstat(struct rev_info *rev,
struct commit *origin, struct commit *head)
{
@@ -1016,7 +1036,8 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
struct commit *origin,
int nr, struct commit **list,
const char *branch_name,
- int quiet)
+ int quiet,
+ const char *range_diff)
{
const char *committer;
const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
@@ -1028,15 +1049,25 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
int need_8bit_cte = 0;
struct pretty_print_context pp = {0};
struct commit *head = list[0];
+ struct strbuf diff = STRBUF_INIT;
if (!cmit_fmt_is_mail(rev->commit_format))
die(_("Cover letter needs email format"));
committer = git_committer_info(0);
+ /* might die from bad user input so try before creating cover letter */
+ if (range_diff) {
+ struct argv_array ranges = ARGV_ARRAY_INIT;
+ infer_diff_ranges(&ranges, range_diff, head);
+ if (get_range_diff(&diff, &ranges))
+ die(_("failed to generate range-diff"));
+ argv_array_clear(&ranges);
+ }
+
if (!use_stdout &&
open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
- return;
+ goto done;
log_write_email_headers(rev, head, &pp.after_subject, &need_8bit_cte);
@@ -1077,6 +1108,17 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
/* We can only do diffstat with a unique reference point */
if (origin)
emit_diffstat(rev, origin, head);
+
+ if (diff.len) {
+ FILE *fp = rev->diffopt.file;
+ fputs(_("Changes since previous version:"), fp);
+ fputs("\n\n", fp);
+ fputs(diff.buf, fp);
+ fputc('\n', fp);
+ }
+
+done:
+ strbuf_release(&diff);
}
static const char *clean_message_id(const char *msg_id)
@@ -1438,6 +1480,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
struct base_tree_info bases;
int show_progress = 0;
struct progress *progress = NULL;
+ const char *range_diff = NULL;
const struct option builtin_format_patch_options[] = {
{ OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
@@ -1511,6 +1554,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
OPT__QUIET(&quiet, N_("don't print the patch filenames")),
OPT_BOOL(0, "progress", &show_progress,
N_("show progress while generating patches")),
+ OPT_STRING(0, "range-diff", &range_diff, N_("rev-range"),
+ N_("show changes against <rev-range> in cover letter")),
OPT_END()
};
@@ -1733,6 +1778,9 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
if (numbered)
rev.total = total + start_number - 1;
+ if (range_diff && !cover_letter)
+ die(_("--range-diff requires --cover-letter"));
+
if (!signature) {
; /* --no-signature inhibits all signatures */
} else if (signature && signature != git_version_string) {
@@ -1764,7 +1812,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
if (thread)
gen_message_id(&rev, "cover");
make_cover_letter(&rev, use_stdout,
- origin, nr, list, branch_name, quiet);
+ origin, nr, list, branch_name, quiet,
+ range_diff);
print_bases(&bases, rev.diffopt.file);
print_signature(rev.diffopt.file);
total++;
diff --git a/t/t7910-branch-diff.sh b/t/t7910-branch-diff.sh
index a7fece8804..edbd69b6f8 100755
--- a/t/t7910-branch-diff.sh
+++ b/t/t7910-branch-diff.sh
@@ -141,4 +141,19 @@ test_expect_success 'changed message' '
test_cmp expected actual
'
+format_patch () {
+ title=$1 &&
+ range=$2 &&
+ test_expect_success "format-patch --range-diff ($title)" '
+ git format-patch --stdout --cover-letter --range-diff=$range \
+ master..unmodified >actual &&
+ grep "= 1: .* s/5/A" actual &&
+ grep "= 2: .* s/4/A" actual &&
+ grep "= 3: .* s/11/B" actual &&
+ grep "= 4: .* s/12/B" actual
+ '
+}
+
+format_patch 'B...C' topic
+
test_done
--
2.17.1.1235.ge295dfb56e
