git.el: Improve error handling for commits.

diff --git a/builtin-merge-base.c b/builtin-merge-base.c
index b08da516e491e7089b1bb178e9a4b05c2ab36539..03fc1c211453f1ed09ee2c6b71d438b0bfbf474f 100644 (file)
--- a/builtin-merge-base.c
+++ b/builtin-merge-base.c
@@ -1,6 +1,7 @@
 #include "builtin.h"
 #include "cache.h"
 #include "commit.h"
+#include "parse-options.h"
 
 static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
 {
@@ -21,8 +22,10 @@ static int show_merge_base(struct commit **rev, int rev_nr, int show_all)
        return 0;
 }
 
-static const char merge_base_usage[] =
-"git merge-base [--all] <commit-id> <commit-id>...";
+static const char * const merge_base_usage[] = {
+       "git merge-base [--all] <commit-id> <commit-id>...",
+       NULL
+};
 
 static struct commit *get_commit_reference(const char *arg)
 {
@@ -44,25 +47,17 @@ int cmd_merge_base(int argc, const char **argv, const char *prefix)
        int rev_nr = 0;
        int show_all = 0;
 
-       git_config(git_default_config, NULL);
-
-       while (1 < argc && argv[1][0] == '-') {
-               const char *arg = argv[1];
-               if (!strcmp(arg, "-a") || !strcmp(arg, "--all"))
-                       show_all = 1;
-               else
-                       usage(merge_base_usage);
-               argc--; argv++;
-       }
-       if (argc < 3)
-               usage(merge_base_usage);
-
-       rev = xmalloc((argc - 1) * sizeof(*rev));
-
-       do {
-               rev[rev_nr++] = get_commit_reference(argv[1]);
-               argc--; argv++;
-       } while (argc > 1);
+       struct option options[] = {
+               OPT_BOOLEAN('a', "all", &show_all, "outputs all common ancestors"),
+               OPT_END()
+       };
 
+       git_config(git_default_config, NULL);
+       argc = parse_options(argc, argv, options, merge_base_usage, 0);
+       if (argc < 2)
+               usage_with_options(merge_base_usage, options);
+       rev = xmalloc(argc * sizeof(*rev));
+       while (argc-- > 0)
+               rev[rev_nr++] = get_commit_reference(*argv++);
        return show_merge_base(rev, rev_nr, show_all);
 }