[PATCH 5/5] interpret-trailers: add --parse convenience option

[Jeff King <peff@peff.net>]

The last few commits have added command line options that
can turn interpret-trailers into a parsing tool. Since
they'd most often be used together, let's provide a
convenient single option for callers to invoke this mode.

This is implemented as a callback rather than a boolean so
that its effect is applied immediately, as if those options
had been specified. Later options can then override them.
E.g.:

  git interpret-trailers --parse --no-normalize

would work.

Signed-off-by: Jeff King <peff@peff.net>
---
 Documentation/git-interpret-trailers.txt |  4 ++++
 builtin/interpret-trailers.c             | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index 6d867e8ab3..ab2d5c7696 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -93,6 +93,10 @@ OPTIONS
 	line, with any existing whitespace continuation folded into a
 	single line.
 
+--parse::
+	A convenience alias for `--only-trailers --only-existing
+	--normalize`.
+
 CONFIGURATION VARIABLES
 -----------------------
 
diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
index ed2d893b4f..70ca855aa6 100644
--- a/builtin/interpret-trailers.c
+++ b/builtin/interpret-trailers.c
@@ -16,6 +16,16 @@ static const char * const git_interpret_trailers_usage[] = {
 	NULL
 };
 
+static int parse_opt_parse(const struct option *opt, const char *arg,
+			   int unset)
+{
+	struct process_trailer_options *v = opt->value;
+	v->only_trailers = 1;
+	v->only_existing = 1;
+	v->normalize = 1;
+	return 0;
+}
+
 int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
 {
 	struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
@@ -27,6 +37,8 @@ int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "only-trailers", &opts.only_trailers, N_("output only the trailers")),
 		OPT_BOOL(0, "only-existing", &opts.only_existing, N_("output only existing trailers")),
 		OPT_BOOL(0, "normalize", &opts.normalize, N_("normalize trailer formatting")),
+		{ OPTION_CALLBACK, 0, "parse", &opts, NULL, N_("set parsing options"),
+			PARSE_OPT_NOARG | PARSE_OPT_NONEG, parse_opt_parse },
 		OPT_STRING_LIST(0, "trailer", &trailers, N_("trailer"),
 				N_("trailer(s) to add")),
 		OPT_END()
-- 
2.14.0.609.gd2d1f7ddf