merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 37 insertions, 3 deletions

diff --git a/third_party/git/trailer.c b/third_party/git/trailer.c
index 0c414f2fed2b..3f7391d793c8 100644
--- a/third_party/git/trailer.c
+++ b/third_party/git/trailer.c
@@ -221,15 +221,13 @@ static char *apply_command(const char *command, const char *arg)
 	struct strbuf cmd = STRBUF_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct child_process cp = CHILD_PROCESS_INIT;
-	const char *argv[] = {NULL, NULL};
 	char *result;
 
 	strbuf_addstr(&cmd, command);
 	if (arg)
 		strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
 
-	argv[0] = cmd.buf;
-	cp.argv = argv;
+	strvec_push(&cp.args, cmd.buf);
 	cp.env = local_repo_env;
 	cp.no_stdin = 1;
 	cp.use_shell = 1;
@@ -1185,3 +1183,39 @@ void format_trailers_from_commit(struct strbuf *out, const char *msg,
 	format_trailer_info(out, &info, opts);
 	trailer_info_release(&info);
 }
+
+void trailer_iterator_init(struct trailer_iterator *iter, const char *msg)
+{
+	struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
+	strbuf_init(&iter->key, 0);
+	strbuf_init(&iter->val, 0);
+	opts.no_divider = 1;
+	trailer_info_get(&iter->info, msg, &opts);
+	iter->cur = 0;
+}
+
+int trailer_iterator_advance(struct trailer_iterator *iter)
+{
+	while (iter->cur < iter->info.trailer_nr) {
+		char *trailer = iter->info.trailers[iter->cur++];
+		int separator_pos = find_separator(trailer, separators);
+
+		if (separator_pos < 1)
+			continue; /* not a real trailer */
+
+		strbuf_reset(&iter->key);
+		strbuf_reset(&iter->val);
+		parse_trailer(&iter->key, &iter->val, NULL,
+			      trailer, separator_pos);
+		unfold_value(&iter->val);
+		return 1;
+	}
+	return 0;
+}
+
+void trailer_iterator_release(struct trailer_iterator *iter)
+{
+	trailer_info_release(&iter->info);
+	strbuf_release(&iter->val);
+	strbuf_release(&iter->key);
+}