builtin/commit: refactor --trailer logic

git-commit adds user trailers to the commit message by passing its
`--trailer` arguments to a child process running `git-interpret-trailers
--in-place`. This logic is broadly useful, not just for git-commit but
for other commands constructing message bodies (e.g. git-tag).

Let's move this logic from git-commit to a new function in the trailer
API, so that it can be re-used in other commands.

Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: John Passaro <john.a.passaro@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/commit.c b/builtin/commit.c
index 5a3248370db85ee074b1023be4f46c15d8ba0fa7..63cd090b6f24dec9ddb21a9fa9d11cd80039ec62 100644 (file)
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -38,6 +38,7 @@
 #include "commit-reach.h"
 #include "commit-graph.h"
 #include "pretty.h"
+#include "trailer.h"
 
 static const char * const builtin_commit_usage[] = {
        N_("git commit [-a | --interactive | --patch] [-s] [-v] [-u<mode>] [--amend]\n"
@@ -1030,14 +1031,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
        fclose(s->fp);
 
        if (trailer_args.nr) {
-               struct child_process run_trailer = CHILD_PROCESS_INIT;
-
-               strvec_pushl(&run_trailer.args, "interpret-trailers",
-                            "--in-place", "--no-divider",
-                            git_path_commit_editmsg(), NULL);
-               strvec_pushv(&run_trailer.args, trailer_args.v);
-               run_trailer.git_cmd = 1;
-               if (run_command(&run_trailer))
+               if (amend_file_with_trailers(git_path_commit_editmsg(), &trailer_args))
                        die(_("unable to pass trailers to --trailers"));
                strvec_clear(&trailer_args);
        }

diff --git a/trailer.c b/trailer.c
index c72ae687099f0d2d21d8dacddf553eabc6ddca8c..724cb78be5fda6ec5090f75b0d92a3c1c54bdba4 100644 (file)
--- a/trailer.c
+++ b/trailer.c
@@ -1170,3 +1170,15 @@ void trailer_iterator_release(struct trailer_iterator *iter)
        strbuf_release(&iter->val);
        strbuf_release(&iter->key);
 }
+
+int amend_file_with_trailers(const char *path, const struct strvec *trailer_args)
+{
+       struct child_process run_trailer = CHILD_PROCESS_INIT;
+
+       run_trailer.git_cmd = 1;
+       strvec_pushl(&run_trailer.args, "interpret-trailers",
+                    "--in-place", "--no-divider",
+                    path, NULL);
+       strvec_pushv(&run_trailer.args, trailer_args->v);
+       return run_command(&run_trailer);
+}

diff --git a/trailer.h b/trailer.h
index 9f42aa75994f3f5b54243239b7ce839b21d7fc45..c364405267a7091767af87190e2335df67c60b37 100644 (file)
--- a/trailer.h
+++ b/trailer.h
@@ -4,6 +4,8 @@
 #include "list.h"
 #include "strbuf.h"
 
+struct strvec;
+
 enum trailer_where {
        WHERE_DEFAULT,
        WHERE_END,
@@ -158,4 +160,11 @@ int trailer_iterator_advance(struct trailer_iterator *iter);
  */
 void trailer_iterator_release(struct trailer_iterator *iter);
 
+/*
+ * Augment a file to add trailers to it by running git-interpret-trailers.
+ * This calls run_command() and its return value is the same (i.e. 0 for
+ * success, various non-zero for other errors). See run-command.h.
+ */
+int amend_file_with_trailers(const char *path, const struct strvec *trailer_args);
+
 #endif /* TRAILER_H */