format-patch: add preset for --commit-list-format

"git format-patch --commit-list-format" enables the user to make their
own format for the commit list in the cover letter. It would be nice to
have a ready to use format to replace shortlog.

Teach make_cover_letter() the "modern" format preset.
This new format is the same as: "log:[%(count)/%(total)] %s".

Signed-off-by: Mirko Faina <mroik@delayed.space>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config/format.adoc

@@ -104,7 +104,7 @@ format.coverLetter::
 format.commitListFormat::
 	When the `--cover-letter-format` option is not given, `format-patch`
 	uses the value of this variable to decide how to format the title of
-	each commit. Default to `shortlog`.
+	each commit. Defaults to `shortlog`.
 
 format.outputDirectory::
 	Set a custom directory to store the resulting files instead of the

Documentation/git-format-patch.adoc

@@ -325,8 +325,8 @@ feeding the result to `git send-email`.
 
 --commit-list-format=<format-spec>::
 	Specify the format in which to generate the commit list of the patch
-	series. The accepted values for format-spec are "shortlog" or a format
-	string prefixed with `log:`.
+	series. The accepted values for format-spec are `shortlog`, `modern` or a
+	format string prefixed with `log:`.
 	e.g. `log: %s (%an)`
 	If not given, defaults to the `format.commitListFormat` configuration
 	variable.

builtin/log.c

@@ -1445,6 +1445,9 @@ static void make_cover_letter(struct rev_info *rev, int use_separate_file,
 		generate_commit_list_cover(rev->diffopt.file, format, list, nr);
 	else if (!strcmp(format, "shortlog"))
 		generate_shortlog_cover_letter(&log, rev, list, nr);
+	else if (!strcmp(format, "modern"))
+		generate_commit_list_cover(rev->diffopt.file, "[%(count)/%(total)] %s",
+					   list, nr);
 	else
 		die(_("'%s' is not a valid format string"), format);
 

t/t4014-format-patch.sh

@@ -392,18 +392,17 @@ test_expect_success 'cover letter with subject, author and count' '
 	test_grep "^\[1/1\] This is a subject (A U Thor)$" patches/0000-cover-letter.patch
 '
 
-test_expect_success 'cover letter with author and count' '
+test_expect_success 'cover letter modern format' '
 	test_when_finished "git reset --hard HEAD~1" &&
 	test_when_finished "rm -rf patches test_file" &&
 	touch test_file &&
 	git add test_file &&
 	git commit -m "This is a subject" &&
-	git format-patch --commit-list-format="log:[%(count)/%(total)] %an" \
-	-o patches HEAD~1 &&
-	test_grep "^\[1/1\] A U Thor$" patches/0000-cover-letter.patch
+	git format-patch --commit-list-format="modern" -o patches HEAD~1 &&
+	test_grep "^\[1/1\] This is a subject$" patches/0000-cover-letter.patch
 '
 
-test_expect_success 'cover letter shortlog' '
+test_expect_success 'cover letter shortlog format' '
 	test_when_finished "git reset --hard HEAD~1" &&
 	test_when_finished "rm -rf expect patches result test_file" &&
 	cat >expect <<-"EOF" &&
@@ -451,6 +450,17 @@ test_expect_success 'cover letter config with count and author' '
 	test_line_count = 2 result
 '
 
+test_expect_success 'cover letter config commitlistformat set to modern' '
+	test_when_finished "rm -rf patches result" &&
+	test_when_finished "git config unset format.coverletter" &&
+	test_when_finished "git config unset format.commitlistformat" &&
+	git config set format.coverletter true &&
+	git config set format.commitlistformat modern &&
+	git format-patch -o patches HEAD~2 &&
+	grep -E "^[[[:digit:]]+/[[:digit:]]+] .*$" patches/0000-cover-letter.patch >result &&
+	test_line_count = 2 result
+'
+
 test_expect_success 'cover letter config commitlistformat set to shortlog' '
 	test_when_finished "rm -rf patches result" &&
 	test_when_finished "git config unset format.coverletter" &&