It can be useful to invoke interpret-trailers for the
primary purpose of parsing existing trailers. But in that
case, we don't want to apply existing ifMissing or ifExists
rules from the config. Let's add a special mode where we
avoid applying those rules. Coupled with --only-trailers,
this gives us a reasonable parsing tool.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
Documentation/git-interpret-trailers.txt | 5 +++++
builtin/interpret-trailers.c | 7 +++++++
t/t7513-interpret-trailers.sh | 15 +++++++++++++++
trailer.c | 7 ++++---
trailer.h | 1 +
5 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index 295dffbd21..b2a8fad248 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -83,6 +83,11 @@ OPTIONS
--only-trailers::
Output only the trailers, not any other parts of the input.
+--only-existing::
+ Output only trailers that exist in the input; do not add any
+ from the command-line or by following configured `trailer.*`
+ rules.
+
CONFIGURATION VARIABLES
-----------------------
diff --git a/builtin/interpret-trailers.c b/builtin/interpret-trailers.c
index afb12c11bc..a49f94ba34 100644
--- a/builtin/interpret-trailers.c
+++ b/builtin/interpret-trailers.c
@@ -25,6 +25,7 @@ int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
OPT_BOOL(0, "in-place", &opts.in_place, N_("edit files in place")),
OPT_BOOL(0, "trim-empty", &opts.trim_empty, N_("trim empty trailers")),
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_STRING_LIST(0, "trailer", &trailers, N_("trailer"),
N_("trailer(s) to add")),
OPT_END()
@@ -33,6 +34,12 @@ int cmd_interpret_trailers(int argc, const char **argv, const char *prefix)
argc = parse_options(argc, argv, prefix, options,
git_interpret_trailers_usage, 0);
+ if (opts.only_existing && trailers.nr)
+ usage_msg_opt(
+ _("--trailer with --only-existing does not make sense"),
+ git_interpret_trailers_usage,
+ options);
+
if (argc) {
int i;
for (i = 0; i < argc; i++)
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index e5b0718ef6..525fd53e5b 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -1312,4 +1312,19 @@ test_expect_success 'only-trailers omits non-trailer in middle of block' '
test_cmp expected actual
'
+test_expect_success 'only existing' '
+ cat >expected <<-\EOF &&
+ existing: existing-value
+ EOF
+ git interpret-trailers \
+ --only-trailers --only-existing >actual <<-\EOF &&
+ my subject
+
+ my body
+
+ existing: existing-value
+ EOF
+ test_cmp expected actual
+'
+
test_done
diff --git a/trailer.c b/trailer.c
index a4ff99f98a..88f6efe523 100644
--- a/trailer.c
+++ b/trailer.c
@@ -991,9 +991,10 @@ void process_trailers(const char *file, struct process_trailer_options *opts,
trailer_end = process_input_file(opts->only_trailers ? NULL : outfile,
sb.buf, &head);
- process_command_line_args(&arg_head, trailers);
-
- process_trailers_lists(&head, &arg_head);
+ if (!opts->only_existing) {
+ process_command_line_args(&arg_head, trailers);
+ process_trailers_lists(&head, &arg_head);
+ }
print_all(outfile, &head, opts);
diff --git a/trailer.h b/trailer.h
index 4270849d80..6356b890ba 100644
--- a/trailer.h
+++ b/trailer.h
@@ -26,6 +26,7 @@ struct process_trailer_options {
int in_place;
int trim_empty;
int only_trailers;
+ int only_existing;
};
#define PROCESS_TRAILER_OPTIONS_INIT {0}
--
2.14.0.609.gd2d1f7ddf
