Merge branch 'dd/format-patch-rfc-updates'

"git format-patch --rfc --subject-prefix=<foo>" used to ignore the
"--subject-prefix" option and used "[RFC PATCH]"; now we will add
"RFC" prefix to whatever subject prefix is specified.

This is a backward compatible change that may deserve a note.

* dd/format-patch-rfc-updates:
  format-patch: --rfc honors what --subject-prefix sets

Documentation/git-format-patch.txt

@@ -221,9 +221,15 @@ populated with placeholder text.
 
 --subject-prefix=<subject prefix>::
  Instead of the standard '[PATCH]' prefix in the subject
- line, instead use '[<subject prefix>]'. This
- allows for useful naming of a patch series, and can be
- combined with the `--numbered` option.
+ line, instead use '[<subject prefix>]'. This can be used
+ to name a patch series, and can be combined with the
+ `--numbered` option.
++
+The configuration variable `format.subjectPrefix` may also be used
+to configure a subject prefix to apply to a given repository for
+all patches. This is often useful on mailing lists which receive
+patches for several repositories and can be used to disambiguate
+the patches (with a value of e.g. "PATCH my-project").
 
 --filename-max-length=<n>::
  Instead of the standard 64 bytes, chomp the generated output
@@ -233,9 +239,9 @@ populated with placeholder text.
  variable, or 64 if unconfigured.
 
 --rfc::
- Alias for `--subject-prefix="RFC PATCH"`. RFC means "Request For
- Comments"; use this when sending an experimental patch for
- discussion rather than application.
+ Prepends "RFC" to the subject prefix (producing "RFC PATCH" by
+ default). RFC means "Request For Comments"; use this when sending
+ an experimental patch for discussion rather than application.
 
 -v <n>::
 --reroll-count=<n>::

builtin/log.c

@@ -1480,19 +1480,16 @@ static int subject_prefix = 0;
 static int subject_prefix_callback(const struct option *opt, const char *arg,
  int unset)
 {
+ struct strbuf *sprefix;
+
  BUG_ON_OPT_NEG(unset);
+ sprefix = opt->value;
  subject_prefix = 1;
- ((struct rev_info *)opt->value)->subject_prefix = arg;
+ strbuf_reset(sprefix);
+ strbuf_addstr(sprefix, arg);
  return 0;
 }
 
-static int rfc_callback(const struct option *opt, const char *arg, int unset)
-{
- BUG_ON_OPT_NEG(unset);
- BUG_ON_OPT_ARG(arg);
- return subject_prefix_callback(opt, "RFC PATCH", unset);
-}
-
 static int numbered_cmdline_opt = 0;
 
 static int numbered_callback(const struct option *opt, const char *arg,
@@ -1920,6 +1917,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
  struct strbuf rdiff_title = STRBUF_INIT;
  struct strbuf sprefix = STRBUF_INIT;
  int creation_factor = -1;
+ int rfc = 0;
 
  const struct option builtin_format_patch_options[] = {
  OPT_CALLBACK_F('n', "numbered", &numbered, NULL,
@@ -1943,15 +1941,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
  N_("mark the series as Nth re-roll")),
  OPT_INTEGER(0, "filename-max-length", &fmt_patch_name_max,
  N_("max length of output filename")),
- OPT_CALLBACK_F(0, "rfc", &rev, NULL,
- N_("use [RFC PATCH] instead of [PATCH]"),
- PARSE_OPT_NOARG | PARSE_OPT_NONEG, rfc_callback),
+ OPT_BOOL(0, "rfc", &rfc, N_("use [RFC PATCH] instead of [PATCH]")),
  OPT_STRING(0, "cover-from-description", &cover_from_description_arg,
  N_("cover-from-description-mode"),
  N_("generate parts of a cover letter based on a branch's description")),
  OPT_FILENAME(0, "description-file", &description_file,
  N_("use branch description from file")),
- OPT_CALLBACK_F(0, "subject-prefix", &rev, N_("prefix"),
+ OPT_CALLBACK_F(0, "subject-prefix", &sprefix, N_("prefix"),
  N_("use [<prefix>] instead of [PATCH]"),
  PARSE_OPT_NONEG, subject_prefix_callback),
  OPT_CALLBACK_F('o', "output-directory", &output_directory,
@@ -2031,11 +2027,11 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
  rev.max_parents = 1;
  rev.diffopt.flags.recursive = 1;
  rev.diffopt.no_free = 1;
- rev.subject_prefix = fmt_patch_subject_prefix;
  memset(&s_r_opt, 0, sizeof(s_r_opt));
  s_r_opt.def = "HEAD";
  s_r_opt.revarg_opt = REVARG_COMMITTISH;
 
+ strbuf_addstr(&sprefix, fmt_patch_subject_prefix);
  if (format_no_prefix)
  diff_set_noprefix(&rev.diffopt);
 
@@ -2063,13 +2059,16 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
  if (cover_from_description_arg)
  cover_from_description_mode = parse_cover_from_description(cover_from_description_arg);
 
+ if (rfc)
+ strbuf_insertstr(&sprefix, 0, "RFC ");
+
  if (reroll_count) {
- strbuf_addf(&sprefix, "%s v%s",
- rev.subject_prefix, reroll_count);
+ strbuf_addf(&sprefix, " v%s", reroll_count);
  rev.reroll_count = reroll_count;
- rev.subject_prefix = sprefix.buf;
  }
 
+ rev.subject_prefix = sprefix.buf;
+
  for (i = 0; i < extra_hdr.nr; i++) {
  strbuf_addstr(&buf, extra_hdr.items[i].string);
  strbuf_addch(&buf, '\n');

t/t4014-format-patch.sh

@@ -1373,7 +1373,27 @@ test_expect_success '--rfc' '
  Subject: [RFC PATCH 1/1] header with . in it
  EOF
  git format-patch -n -1 --stdout --rfc >patch &&
- grep ^Subject: patch >actual &&
+ grep "^Subject:" patch >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success '--rfc does not overwrite prefix' '
+ cat >expect <<-\EOF &&
+ Subject: [RFC PATCH foobar 1/1] header with . in it
+ EOF
+ git -c format.subjectPrefix="PATCH foobar" \
+ format-patch -n -1 --stdout --rfc >patch &&
+ grep "^Subject:" patch >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success '--rfc is argument order independent' '
+ cat >expect <<-\EOF &&
+ Subject: [RFC PATCH foobar 1/1] header with . in it
+ EOF
+ git format-patch -n -1 --stdout --rfc \
+ --subject-prefix="PATCH foobar" >patch &&
+ grep "^Subject:" patch >actual &&
  test_cmp expect actual
 '