[PATCH] commit-tree: utilize parse-options api

[Brandon <brandon1024.br@gmail.com>]

From: Brandon Richardson <brandon1024.br@gmail.com>

Rather than parse options manually, which is both difficult to
read and error prone, parse options supplied to commit-tree
using the parse-options api.

It was discovered that the --no-gpg-sign option was documented
but not implemented in 55ca3f99, and the existing implementation
would attempt to translate the option as a tree oid.It was also
suggested in 55ca3f99 that commit-tree should be migrated to
utilize the parse-options api, which could help prevent mistakes
like this in the future. Hence this change.

Signed-off-by: Brandon Richardson <brandon1024.br@gmail.com>
---

Notes:
    GitHub Pull Request: https://github.com/brandon1024/git/pull/1
    Travis CI Results: https://travis-ci.com/brandon1024/git/builds/102337393

 builtin/commit-tree.c | 162 ++++++++++++++++++++++++------------------
 1 file changed, 92 insertions(+), 70 deletions(-)

diff --git a/builtin/commit-tree.c b/builtin/commit-tree.c
index 12cc403bd7..310f38d000 100644
--- a/builtin/commit-tree.c
+++ b/builtin/commit-tree.c
@@ -12,8 +12,14 @@
 #include "builtin.h"
 #include "utf8.h"
 #include "gpg-interface.h"
+#include "parse-options.h"
+#include "string-list.h"
 
-static const char commit_tree_usage[] = "git commit-tree [(-p <sha1>)...] [-S[<keyid>]] [-m <message>] [-F <file>] <sha1>";
+static const char * const builtin_commit_tree_usage[] = {
+	N_("git commit-tree [(-p <parent>)...] [-S[<keyid>]] [(-m <message>)...] "
+		"[(-F <file>)...] <tree>"),
+	NULL
+};
 
 static const char *sign_commit;
 
@@ -39,87 +45,103 @@ static int commit_tree_config(const char *var, const char *value, void *cb)
 	return git_default_config(var, value, cb);
 }
 
+static int parse_parent_arg_callback(const struct option *opt,
+		const char *arg, int unset)
+{
+	struct object_id oid;
+	struct commit_list **parents = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
+	if (!arg)
+		return 1;
+	if (get_oid_commit(arg, &oid))
+		die("Not a valid object name %s", arg);
+
+	assert_oid_type(&oid, OBJ_COMMIT);
+	new_parent(lookup_commit(the_repository, &oid), parents);
+	return 0;
+}
+
+static int parse_message_arg_callback(const struct option *opt,
+		const char *arg, int unset)
+{
+	struct strbuf *buf = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
+	if (!arg)
+		return 1;
+	if (buf->len)
+		strbuf_addch(buf, '\n');
+	strbuf_addstr(buf, arg);
+	strbuf_complete_line(buf);
+
+	return 0;
+}
+
+static int parse_file_arg_callback(const struct option *opt,
+		const char *arg, int unset)
+{
+	int fd;
+	struct strbuf *buf = opt->value;
+
+	BUG_ON_OPT_NEG(unset);
+
+	if (!arg)
+		return 1;
+	if (buf->len)
+		strbuf_addch(buf, '\n');
+	if (!strcmp(arg, "-"))
+		fd = 0;
+	else {
+		fd = open(arg, O_RDONLY);
+		if (fd < 0)
+			die_errno("git commit-tree: failed to open '%s'", arg);
+	}
+	if (strbuf_read(buf, fd, 0) < 0)
+		die_errno("git commit-tree: failed to read '%s'", arg);
+	if (fd && close(fd))
+		die_errno("git commit-tree: failed to close '%s'", arg);
+
+	return 0;
+}
+
 int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 {
-	int i, got_tree = 0;
+	static struct strbuf buffer = STRBUF_INIT;
 	struct commit_list *parents = NULL;
 	struct object_id tree_oid;
 	struct object_id commit_oid;
-	struct strbuf buffer = STRBUF_INIT;
+
+    struct option builtin_commit_tree_options[] = {
+		{ OPTION_CALLBACK, 'p', NULL, &parents, "parent",
+		  N_("id of a parent commit object"), PARSE_OPT_NONEG,
+		  parse_parent_arg_callback },
+		{ OPTION_CALLBACK, 'm', NULL, &buffer, N_("message"),
+		  N_("commit message"), PARSE_OPT_NONEG,
+		  parse_message_arg_callback },
+		{ OPTION_CALLBACK, 'F', NULL, &buffer, N_("file"),
+		  N_("read commit log message from file"), PARSE_OPT_NONEG,
+		  parse_file_arg_callback },
+		{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
+		  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+		OPT_END()
+    };
 
 	git_config(commit_tree_config, NULL);
 
 	if (argc < 2 || !strcmp(argv[1], "-h"))
-		usage(commit_tree_usage);
-
-	for (i = 1; i < argc; i++) {
-		const char *arg = argv[i];
-		if (!strcmp(arg, "-p")) {
-			struct object_id oid;
-			if (argc <= ++i)
-				usage(commit_tree_usage);
-			if (get_oid_commit(argv[i], &oid))
-				die("Not a valid object name %s", argv[i]);
-			assert_oid_type(&oid, OBJ_COMMIT);
-			new_parent(lookup_commit(the_repository, &oid),
-						 &parents);
-			continue;
-		}
+		usage_with_options(builtin_commit_tree_usage, builtin_commit_tree_options);
 
-		if (!strcmp(arg, "--gpg-sign")) {
-		    sign_commit = "";
-		    continue;
-		}
-
-		if (skip_prefix(arg, "-S", &sign_commit) ||
-			skip_prefix(arg, "--gpg-sign=", &sign_commit))
-			continue;
-
-		if (!strcmp(arg, "--no-gpg-sign")) {
-			sign_commit = NULL;
-			continue;
-		}
+	argc = parse_options(argc, argv, prefix, builtin_commit_tree_options,
+			builtin_commit_tree_usage, 0);
 
-		if (!strcmp(arg, "-m")) {
-			if (argc <= ++i)
-				usage(commit_tree_usage);
-			if (buffer.len)
-				strbuf_addch(&buffer, '\n');
-			strbuf_addstr(&buffer, argv[i]);
-			strbuf_complete_line(&buffer);
-			continue;
-		}
-
-		if (!strcmp(arg, "-F")) {
-			int fd;
-
-			if (argc <= ++i)
-				usage(commit_tree_usage);
-			if (buffer.len)
-				strbuf_addch(&buffer, '\n');
-			if (!strcmp(argv[i], "-"))
-				fd = 0;
-			else {
-				fd = open(argv[i], O_RDONLY);
-				if (fd < 0)
-					die_errno("git commit-tree: failed to open '%s'",
-						  argv[i]);
-			}
-			if (strbuf_read(&buffer, fd, 0) < 0)
-				die_errno("git commit-tree: failed to read '%s'",
-					  argv[i]);
-			if (fd && close(fd))
-				die_errno("git commit-tree: failed to close '%s'",
-					  argv[i]);
-			continue;
-		}
+	if (argc != 1)
+		die("Must give exactly one tree");
 
-		if (get_oid_tree(arg, &tree_oid))
-			die("Not a valid object name %s", arg);
-		if (got_tree)
-			die("Cannot give more than one trees");
-		got_tree = 1;
-	}
+	if (get_oid_tree(argv[0], &tree_oid))
+		die("Not a valid object name %s", argv[0]);
 
 	if (!buffer.len) {
 		if (strbuf_read(&buffer, 0, 0) < 0)
-- 
2.21.0