[PATCH/WIP v3 31/31] am: implement -S/--gpg-sign, commit.gpgsign

[Paul Tan <pyokagan@gmail.com>]

Since 3b4e395 (am: add the --gpg-sign option, 2014-02-01), git-am.sh
supported the --gpg-sign option, and would pass it to git-commit-tree,
thus GPG-signing the commit object.

Re-implement this option in builtin/am.c.

git-commit-tree would also sign the commit by default if the
commit.gpgsign setting is true. Since we do not run commit-tree, we
re-implement this behavior by handling the commit.gpgsign setting
ourselves.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
---
 builtin/am.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/builtin/am.c b/builtin/am.c
index 608a2da..91dae92 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -134,6 +134,8 @@ struct am_state {
 
 	int ignore_date;
 
+	const char *sign_commit;
+
 	int rebasing;
 };
 
@@ -143,6 +145,7 @@ struct am_state {
 static void am_state_init(struct am_state *state)
 {
 	const char *quiet;
+	int sign_commit;
 
 	memset(state, 0, sizeof(*state));
 
@@ -164,6 +167,9 @@ static void am_state_init(struct am_state *state)
 	state->scissors = SCISSORS_UNSET;
 
 	argv_array_init(&state->git_apply_opts);
+
+	if (!git_config_get_bool("commit.gpgsign", &sign_commit))
+		state->sign_commit = sign_commit ? "" : NULL;
 }
 
 /**
@@ -1143,7 +1149,7 @@ static void do_commit(const struct am_state *state)
 			state->ignore_date ? "" : state->author_date.buf, 1);
 
 	if (commit_tree(state->msg.buf, state->msg.len, tree, parents, commit,
-				author, NULL))
+				author, state->sign_commit))
 		die(_("failed to write commit object"));
 
 	reflog_msg = getenv("GIT_REFLOG_ACTION");
@@ -1535,6 +1541,9 @@ static struct option am_options[] = {
 		N_("lie about committer date")),
 	OPT_BOOL(0, "ignore-date", &state.ignore_date,
 		N_("use current timestamp for author date")),
+	{ OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
+	  N_("GPG-sign commits"),
+	  PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
 		N_("(internal use for git-rebase)")),
 	OPT_END()
-- 
2.1.4