Allow cloning to an existing empty directory

diff --git a/builtin-rev-parse.c b/builtin-rev-parse.c
index ab3e85054e174d2d328c625f1db744854b62f5f7..81d5a6ffc9ff1c149bfb68f976a9e66c307cae1d 100644 (file)
--- a/builtin-rev-parse.c
+++ b/builtin-rev-parse.c
@@ -241,6 +241,36 @@ static int try_difference(const char *arg)
        return 0;
 }
 
+static int try_parent_shorthands(const char *arg)
+{
+       char *dotdot;
+       unsigned char sha1[20];
+       struct commit *commit;
+       struct commit_list *parents;
+       int parents_only;
+
+       if ((dotdot = strstr(arg, "^!")))
+               parents_only = 0;
+       else if ((dotdot = strstr(arg, "^@")))
+               parents_only = 1;
+
+       if (!dotdot || dotdot[2])
+               return 0;
+
+       *dotdot = 0;
+       if (get_sha1(arg, sha1))
+               return 0;
+
+       if (!parents_only)
+               show_rev(NORMAL, sha1, arg);
+       commit = lookup_commit_reference(sha1);
+       for (parents = commit->parents; parents; parents = parents->next)
+               show_rev(parents_only ? NORMAL : REVERSED,
+                               parents->item->object.sha1, arg);
+
+       return 1;
+}
+
 static int parseopt_dump(const struct option *o, const char *arg, int unset)
 {
        struct strbuf *parsed = o->value;
@@ -268,7 +298,7 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
 {
        static int keep_dashdash = 0;
        static char const * const parseopt_usage[] = {
-               "git-rev-parse --parseopt [options] -- [<args>...]",
+               "git rev-parse --parseopt [options] -- [<args>...]",
                NULL
        };
        static struct option parseopt_opts[] = {
@@ -277,19 +307,17 @@ static int cmd_parseopt(int argc, const char **argv, const char *prefix)
                OPT_END(),
        };
 
-       struct strbuf sb, parsed;
+       struct strbuf sb = STRBUF_INIT, parsed = STRBUF_INIT;
        const char **usage = NULL;
        struct option *opts = NULL;
        int onb = 0, osz = 0, unb = 0, usz = 0;
 
-       strbuf_init(&parsed, 0);
        strbuf_addstr(&parsed, "set --");
        argc = parse_options(argc, argv, parseopt_opts, parseopt_usage,
                             PARSE_OPT_KEEP_DASHDASH);
        if (argc < 1 || strcmp(argv[0], "--"))
                usage_with_options(parseopt_usage, parseopt_opts);
 
-       strbuf_init(&sb, 0);
        /* get the usage up to the first line with a -- on it */
        for (;;) {
                if (strbuf_getline(&sb, stdin, '\n') == EOF)
@@ -387,7 +415,7 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
                return cmd_parseopt(argc - 1, argv + 1, prefix);
 
        prefix = setup_git_directory();
-       git_config(git_default_config);
+       git_config(git_default_config, NULL);
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
 
@@ -573,6 +601,8 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
                /* Not a flag argument */
                if (try_difference(arg))
                        continue;
+               if (try_parent_shorthands(arg))
+                       continue;
                name = arg;
                type = NORMAL;
                if (*arg == '^') {