text: /*
   * rev-parse.c
   *
   * Copyright (C) Linus Torvalds, 2005
   */
  #include "cache.h"
  #include "commit.h"
  #include "refs.h"
  #include "quote.h"
  #include "builtin.h"
  #include "parse-options.h"
  #include "diff.h"
  #include "revision.h"
  #include "split-index.h"
  
  #define DO_REVS		1
  #define DO_NOREV	2
  #define DO_FLAGS	4
  #define DO_NONFLAGS	8
  static int filter = ~0;
  
  static const char *def;
  
  #define NORMAL 0
  #define REVERSED 1
  static int show_type = NORMAL;
  
  #define SHOW_SYMBOLIC_ASIS 1
  #define SHOW_SYMBOLIC_FULL 2
  static int symbolic;
  static int abbrev;
  static int abbrev_ref;
  static int abbrev_ref_strict;
  static int output_sq;
  
  static int stuck_long;
  static struct string_list *ref_excludes;
  
  /*
   * Some arguments are relevant "revision" arguments,
   * others are about output format or other details.
   * This sorts it all out.
   */
  static int is_rev_argument(const char *arg)
  {
  	static const char *rev_args[] = {
  		"--all",
  		"--bisect",
  		"--dense",
  		"--branches=",
  		"--branches",
  		"--header",
  		"--ignore-missing",
  		"--max-age=",
  		"--max-count=",
  		"--min-age=",
  		"--no-merges",
  		"--min-parents=",
  		"--no-min-parents",
  		"--max-parents=",
  		"--no-max-parents",
  		"--objects",
  		"--objects-edge",
  		"--parents",
  		"--pretty",
  		"--remotes=",
  		"--remotes",
  		"--glob=",
  		"--sparse",
  		"--tags=",
  		"--tags",
  		"--topo-order",
  		"--date-order",
  		"--unpacked",
  		NULL
  	};
  	const char **p = rev_args;
  
  	/* accept -<digit>, like traditional "head" */
  	if ((*arg == '-') && isdigit(arg[1]))
  		return 1;
  
  	for (;;) {
  		const char *str = *p++;
  		int len;
  		if (!str)
  			return 0;
  		len = strlen(str);
  		if (!strcmp(arg, str) ||
  		    (str[len-1] == '=' && !strncmp(arg, str, len)))
  			return 1;
  	}
  }
  
  /* Output argument as a string, either SQ or normal */
  static void show(const char *arg)
  {
  	if (output_sq) {
  		int sq = '\'', ch;
  
  		putchar(sq);
  		while ((ch = *arg++)) {
  			if (ch == sq)
  				fputs("'\\'", stdout);
  			putchar(ch);
  		}
  		putchar(sq);
  		putchar(' ');
  	}
  	else
  		puts(arg);
  }
  
  /* Like show(), but with a negation prefix according to type */
  static void show_with_type(int type, const char *arg)
  {
  	if (type != show_type)
  		putchar('^');
  	show(arg);
  }
  
  /* Output a revision, only if filter allows it */
  static void show_rev(int type, const unsigned char *sha1, const char *name)
  {
  	if (!(filter & DO_REVS))
  		return;
  	def = NULL;
  
  	if ((symbolic || abbrev_ref) && name) {
  		if (symbolic == SHOW_SYMBOLIC_FULL || abbrev_ref) {
  			unsigned char discard[20];
  			char *full;
  
  			switch (dwim_ref(name, strlen(name), discard, &full)) {
  			case 0:
  				/*
  				 * Not found -- not a ref.  We could
  				 * emit "name" here, but symbolic-full
  				 * users are interested in finding the
  				 * refs spelled in full, and they would
  				 * need to filter non-refs if we did so.
  				 */
  				break;
  			case 1: /* happy */
  				if (abbrev_ref)
  					full = shorten_unambiguous_ref(full,
  						abbrev_ref_strict);
  				show_with_type(type, full);
  				break;
  			default: /* ambiguous */
  				error("refname '%s' is ambiguous", name);
  				break;
  			}
  			free(full);
  		} else {
  			show_with_type(type, name);
  		}
  	}
  	else if (abbrev)
  		show_with_type(type, find_unique_abbrev(sha1, abbrev));
  	else
  		show_with_type(type, sha1_to_hex(sha1));
  }
  
  /* Output a flag, only if filter allows it. */
  static int show_flag(const char *arg)
  {
  	if (!(filter & DO_FLAGS))
  		return 0;
  	if (filter & (is_rev_argument(arg) ? DO_REVS : DO_NOREV)) {
  		show(arg);
  		return 1;
  	}
  	return 0;
  }
  
  static int show_default(void)
  {
  	const char *s = def;
  
  	if (s) {
  		unsigned char sha1[20];
  
  		def = NULL;
  		if (!get_sha1(s, sha1)) {
  			show_rev(NORMAL, sha1, s);
  			return 1;
  		}
  	}
  	return 0;
  }
  
  static int show_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  {
  	if (ref_excluded(ref_excludes, refname))
  		return 0;
  	show_rev(NORMAL, sha1, refname);
  	return 0;
  }
  
  static int anti_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
  {
  	show_rev(REVERSED, sha1, refname);
  	return 0;
  }
  
  static int show_abbrev(const unsigned char *sha1, void *cb_data)
  {
  	show_rev(NORMAL, sha1, NULL);
  	return 0;
  }
  
  static void show_datestring(const char *flag, const char *datestr)
  {
  	static char buffer[100];
  
  	/* date handling requires both flags and revs */
  	if ((filter & (DO_FLAGS | DO_REVS)) != (DO_FLAGS | DO_REVS))
  		return;
  	snprintf(buffer, sizeof(buffer), "%s%lu", flag, approxidate(datestr));
  	show(buffer);
  }
  
  static int show_file(const char *arg, int output_prefix)
  {
  	show_default();
  	if ((filter & (DO_NONFLAGS|DO_NOREV)) == (DO_NONFLAGS|DO_NOREV)) {
  		if (output_prefix) {
  			const char *prefix = startup_info->prefix;
  			show(prefix_filename(prefix,
  					     prefix ? strlen(prefix) : 0,
  					     arg));
  		} else
  			show(arg);
  		return 1;
  	}
  	return 0;
  }
  
  static int try_difference(const char *arg)
  {
  	char *dotdot;
  	unsigned char sha1[20];
  	unsigned char end[20];
  	const char *next;
  	const char *this;
  	int symmetric;
  	static const char head_by_default[] = "HEAD";
  
  	if (!(dotdot = strstr(arg, "..")))
  		return 0;
  	next = dotdot + 2;
  	this = arg;
  	symmetric = (*next == '.');
  
  	*dotdot = 0;
  	next += symmetric;
  
  	if (!*next)
  		next = head_by_default;
  	if (dotdot == arg)
  		this = head_by_default;
  
  	if (this == head_by_default && next == head_by_default &&
  	    !symmetric) {
  		/*
  		 * Just ".."?  That is not a range but the
  		 * pathspec for the parent directory.
  		 */
  		*dotdot = '.';
  		return 0;
  	}
  
  	if (!get_sha1_committish(this, sha1) && !get_sha1_committish(next, end)) {
  		show_rev(NORMAL, end, next);
  		show_rev(symmetric ? NORMAL : REVERSED, sha1, this);
  		if (symmetric) {
  			struct commit_list *exclude;
  			struct commit *a, *b;
  			a = lookup_commit_reference(sha1);
  			b = lookup_commit_reference(end);
  			exclude = get_merge_bases(a, b, 1);
  			while (exclude) {
  				struct commit_list *n = exclude->next;
  				show_rev(REVERSED,
  					 exclude->item->object.sha1,NULL);
  				free(exclude);
  				exclude = n;
  			}
  		}
  		*dotdot = '.';
  		return 1;
  	}
  	*dotdot = '.';
  	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_committish(arg, sha1)) {
  		*dotdot = '^';
  		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);
  
  	*dotdot = '^';
  	return 1;
  }
  
  static int parseopt_dump(const struct option *o, const char *arg, int unset)
  {
  	struct strbuf *parsed = o->value;
  	if (unset)
  		strbuf_addf(parsed, " --no-%s", o->long_name);
  	else if (o->short_name && (o->long_name == NULL || !stuck_long))
  		strbuf_addf(parsed, " -%c", o->short_name);
  	else
  		strbuf_addf(parsed, " --%s", o->long_name);
  	if (arg) {
  		if (!stuck_long)
  			strbuf_addch(parsed, ' ');
  		else if (o->long_name)
  			strbuf_addch(parsed, '=');
  		sq_quote_buf(parsed, arg);
  	}
  	return 0;
  }
  
  static const char *skipspaces(const char *s)
  {
  	while (isspace(*s))
  		s++;
  	return s;
  }
  
  static int cmd_parseopt(int argc, const char **argv, const char *prefix)
  {
  	static int keep_dashdash = 0, stop_at_non_option = 0;
  	static char const * const parseopt_usage[] = {
  		N_("git rev-parse --parseopt [options] -- [<args>...]"),
  		NULL
  	};
  	static struct option parseopt_opts[] = {
  		OPT_BOOL(0, "keep-dashdash", &keep_dashdash,
  					N_("keep the `--` passed as an arg")),
  		OPT_BOOL(0, "stop-at-non-option", &stop_at_non_option,
  					N_("stop parsing after the "
  					   "first non-option argument")),
  		OPT_BOOL(0, "stuck-long", &stuck_long,
  					N_("output in stuck long form")),
  		OPT_END(),
  	};
  
  	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_addstr(&parsed, "set --");
  	argc = parse_options(argc, argv, prefix, parseopt_opts, parseopt_usage,
  	                     PARSE_OPT_KEEP_DASHDASH);
  	if (argc < 1 || strcmp(argv[0], "--"))
  		usage_with_options(parseopt_usage, parseopt_opts);
  
  	/* get the usage up to the first line with a -- on it */
  	for (;;) {
  		if (strbuf_getline(&sb, stdin, '\n') == EOF)
  			die("premature end of input");
  		ALLOC_GROW(usage, unb + 1, usz);
  		if (!strcmp("--", sb.buf)) {
  			if (unb < 1)
  				die("no usage string given before the `--' separator");
  			usage[unb] = NULL;
  			break;
  		}
  		usage[unb++] = strbuf_detach(&sb, NULL);
  	}
  
  	/* parse: (<short>|<short>,<long>|<long>)[*=?!]*<arghint>? SP+ <help> */
  	while (strbuf_getline(&sb, stdin, '\n') != EOF) {
  		const char *s;
  		const char *end;
  		struct option *o;
  
  		if (!sb.len)
  			continue;
  
  		ALLOC_GROW(opts, onb + 1, osz);
  		memset(opts + onb, 0, sizeof(opts[onb]));
  
  		o = &opts[onb++];
  		s = strchr(sb.buf, ' ');
  		if (!s || *sb.buf == ' ') {
  			o->type = OPTION_GROUP;
  			o->help = xstrdup(skipspaces(sb.buf));
  			continue;
  		}
  
  		o->type = OPTION_CALLBACK;
  		o->help = xstrdup(skipspaces(s));
  		o->value = &parsed;
  		o->flags = PARSE_OPT_NOARG;
  		o->callback = &parseopt_dump;
  
  		/* Possible argument name hint */
  		end = s;
  		while (s > sb.buf && strchr("*=?!", s[-1]) == NULL)
  			--s;
  		if (s != sb.buf && s != end)
  			o->argh = xmemdupz(s, end - s);
  		if (s == sb.buf)
  			s = end;
  
  		while (s > sb.buf && strchr("*=?!", s[-1])) {
  			switch (*--s) {
  			case '=':
  				o->flags &= ~PARSE_OPT_NOARG;
  				break;
  			case '?':
  				o->flags &= ~PARSE_OPT_NOARG;
  				o->flags |= PARSE_OPT_OPTARG;
  				break;
  			case '!':
  				o->flags |= PARSE_OPT_NONEG;
  				break;
  			case '*':
  				o->flags |= PARSE_OPT_HIDDEN;
  				break;
  			}
  		}
  
  		if (s - sb.buf == 1) /* short option only */
  			o->short_name = *sb.buf;
  		else if (sb.buf[1] != ',') /* long option only */
  			o->long_name = xmemdupz(sb.buf, s - sb.buf);
  		else {
  			o->short_name = *sb.buf;
  			o->long_name = xmemdupz(sb.buf + 2, s - sb.buf - 2);
  		}
  	}
  	strbuf_release(&sb);
  
  	/* put an OPT_END() */
  	ALLOC_GROW(opts, onb + 1, osz);
  	memset(opts + onb, 0, sizeof(opts[onb]));
  	argc = parse_options(argc, argv, prefix, opts, usage,
  			(keep_dashdash ? PARSE_OPT_KEEP_DASHDASH : 0) |
  			(stop_at_non_option ? PARSE_OPT_STOP_AT_NON_OPTION : 0) |
  			PARSE_OPT_SHELL_EVAL);
  
  	strbuf_addf(&parsed, " --");
  	sq_quote_argv(&parsed, argv, 0);
  	puts(parsed.buf);
  	return 0;
  }
  
  static int cmd_sq_quote(int argc, const char **argv)
  {
  	struct strbuf buf = STRBUF_INIT;
  
  	if (argc)
  		sq_quote_argv(&buf, argv, 0);
  	printf("%s\n", buf.buf);
  	strbuf_release(&buf);
  
  	return 0;
  }
  
  static void die_no_single_rev(int quiet)
  {
  	if (quiet)
  		exit(1);
  	else
  		die("Needed a single revision");
  }
  
  static const char builtin_rev_parse_usage[] =
  N_("git rev-parse --parseopt [options] -- [<args>...]\n"
     "   or: git rev-parse --sq-quote [<arg>...]\n"
     "   or: git rev-parse [options] [<arg>...]\n"
     "\n"
     "Run \"git rev-parse --parseopt -h\" for more information on the first usage.");
  
  int cmd_rev_parse(int argc, const char **argv, const char *prefix)
  {
  	int i, as_is = 0, verify = 0, quiet = 0, revs_count = 0, type = 0;
  	int has_dashdash = 0;
  	int output_prefix = 0;
  	unsigned char sha1[20];
  	unsigned int flags = 0;
  	const char *name = NULL;
  	struct object_context unused;
  
  	if (argc > 1 && !strcmp("--parseopt", argv[1]))
  		return cmd_parseopt(argc - 1, argv + 1, prefix);
  
  	if (argc > 1 && !strcmp("--sq-quote", argv[1]))
  		return cmd_sq_quote(argc - 2, argv + 2);
  
  	if (argc > 1 && !strcmp("-h", argv[1]))
  		usage(builtin_rev_parse_usage);
  
  	for (i = 1; i < argc; i++) {
  		if (!strcmp(argv[i], "--")) {
  			has_dashdash = 1;
  			break;
  		}
  	}
  
  	prefix = setup_git_directory();
  	git_config(git_default_config, NULL);
  	for (i = 1; i < argc; i++) {
  		const char *arg = argv[i];
  
  		if (as_is) {
  			if (show_file(arg, output_prefix) && as_is < 2)
  				verify_filename(prefix, arg, 0);
  			continue;
  		}
  		if (!strcmp(arg,"-n")) {
  			if (++i >= argc)
  				die("-n requires an argument");
  			if ((filter & DO_FLAGS) && (filter & DO_REVS)) {
  				show(arg);
  				show(argv[i]);
  			}
  			continue;
  		}
  		if (starts_with(arg, "-n")) {
  			if ((filter & DO_FLAGS) && (filter & DO_REVS))
  				show(arg);
  			continue;
  		}
  
  		if (*arg == '-') {
  			if (!strcmp(arg, "--")) {
  				as_is = 2;
  				/* Pass on the "--" if we show anything but files.. */
  				if (filter & (DO_FLAGS | DO_REVS))
  					show_file(arg, 0);
  				continue;
  			}
  			if (!strcmp(arg, "--default")) {
  				def = argv[++i];
  				if (!def)
  					die("--default requires an argument");
  				continue;
  			}
  			if (!strcmp(arg, "--prefix")) {
  				prefix = argv[++i];
  				if (!prefix)
  					die("--prefix requires an argument");
  				startup_info->prefix = prefix;
  				output_prefix = 1;
  				continue;
  			}
  			if (!strcmp(arg, "--revs-only")) {
  				filter &= ~DO_NOREV;
  				continue;
  			}
  			if (!strcmp(arg, "--no-revs")) {
  				filter &= ~DO_REVS;
  				continue;
  			}
  			if (!strcmp(arg, "--flags")) {
  				filter &= ~DO_NONFLAGS;
  				continue;
  			}
  			if (!strcmp(arg, "--no-flags")) {
  				filter &= ~DO_FLAGS;
  				continue;
  			}
  			if (!strcmp(arg, "--verify")) {
  				filter &= ~(DO_FLAGS|DO_NOREV);
  				verify = 1;
  				continue;
  			}
  			if (!strcmp(arg, "--quiet") || !strcmp(arg, "-q")) {
  				quiet = 1;
  				flags |= GET_SHA1_QUIETLY;
  				continue;
  			}
  			if (!strcmp(arg, "--short") ||
  			    starts_with(arg, "--short=")) {
  				filter &= ~(DO_FLAGS|DO_NOREV);
  				verify = 1;
  				abbrev = DEFAULT_ABBREV;
  				if (arg[7] == '=')
  					abbrev = strtoul(arg + 8, NULL, 10);
  				if (abbrev < MINIMUM_ABBREV)
  					abbrev = MINIMUM_ABBREV;
  				else if (40 <= abbrev)
  					abbrev = 40;
  				continue;
  			}
  			if (!strcmp(arg, "--sq")) {
  				output_sq = 1;
  				continue;
  			}
  			if (!strcmp(arg, "--not")) {
  				show_type ^= REVERSED;
  				continue;
  			}
  			if (!strcmp(arg, "--symbolic")) {
  				symbolic = SHOW_SYMBOLIC_ASIS;
  				continue;
  			}
  			if (!strcmp(arg, "--symbolic-full-name")) {
  				symbolic = SHOW_SYMBOLIC_FULL;
  				continue;
  			}
  			if (starts_with(arg, "--abbrev-ref") &&
  			    (!arg[12] || arg[12] == '=')) {
  				abbrev_ref = 1;
  				abbrev_ref_strict = warn_ambiguous_refs;
  				if (arg[12] == '=') {
  					if (!strcmp(arg + 13, "strict"))
  						abbrev_ref_strict = 1;
  					else if (!strcmp(arg + 13, "loose"))
  						abbrev_ref_strict = 0;
  					else
  						die("unknown mode for %s", arg);
  				}
  				continue;
  			}
  			if (!strcmp(arg, "--all")) {
  				for_each_ref(show_reference, NULL);
  				continue;
  			}
  			if (starts_with(arg, "--disambiguate=")) {
  				for_each_abbrev(arg + 15, show_abbrev, NULL);
  				continue;
  			}
  			if (!strcmp(arg, "--bisect")) {
  				for_each_ref_in("refs/bisect/bad", show_reference, NULL);
  				for_each_ref_in("refs/bisect/good", anti_reference, NULL);
  				continue;
  			}
  			if (starts_with(arg, "--branches=")) {
  				for_each_glob_ref_in(show_reference, arg + 11,
  					"refs/heads/", NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (!strcmp(arg, "--branches")) {
  				for_each_branch_ref(show_reference, NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (starts_with(arg, "--tags=")) {
  				for_each_glob_ref_in(show_reference, arg + 7,
  					"refs/tags/", NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (!strcmp(arg, "--tags")) {
  				for_each_tag_ref(show_reference, NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (starts_with(arg, "--glob=")) {
  				for_each_glob_ref(show_reference, arg + 7, NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (starts_with(arg, "--remotes=")) {
  				for_each_glob_ref_in(show_reference, arg + 10,
  					"refs/remotes/", NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (!strcmp(arg, "--remotes")) {
  				for_each_remote_ref(show_reference, NULL);
  				clear_ref_exclusion(&ref_excludes);
  				continue;
  			}
  			if (starts_with(arg, "--exclude=")) {
  				add_ref_exclusion(&ref_excludes, arg + 10);
  				continue;
  			}
  			if (!strcmp(arg, "--local-env-vars")) {
  				int i;
  				for (i = 0; local_repo_env[i]; i++)
  					printf("%s\n", local_repo_env[i]);
  				continue;
  			}
  			if (!strcmp(arg, "--show-toplevel")) {
  				const char *work_tree = get_git_work_tree();
  				if (work_tree)
  					puts(work_tree);
  				continue;
  			}
  			if (!strcmp(arg, "--show-prefix")) {
  				if (prefix)
  					puts(prefix);
  				else
  					putchar('\n');
  				continue;
  			}
  			if (!strcmp(arg, "--show-cdup")) {
  				const char *pfx = prefix;
  				if (!is_inside_work_tree()) {
  					const char *work_tree =
  						get_git_work_tree();
  					if (work_tree)
  						printf("%s\n", work_tree);
  					continue;
  				}
  				while (pfx) {
  					pfx = strchr(pfx, '/');
  					if (pfx) {
  						pfx++;
  						printf("../");
  					}
  				}
  				putchar('\n');
  				continue;
  			}
  			if (!strcmp(arg, "--git-dir")) {
  				const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
  				char *cwd;
  				int len;
  				if (gitdir) {
  					puts(gitdir);
  					continue;
  				}
  				if (!prefix) {
  					puts(".git");
  					continue;
  				}
  				cwd = xgetcwd();
  				len = strlen(cwd);
  				printf("%s%s.git\n", cwd, len && cwd[len-1] != '/' ? "/" : "");
  				free(cwd);
  				continue;
  			}
  			if (!strcmp(arg, "--resolve-git-dir")) {
  				const char *gitdir = argv[++i];
  				if (!gitdir)
  					die("--resolve-git-dir requires an argument");
  				gitdir = resolve_gitdir(gitdir);
  				if (!gitdir)
  					die("not a gitdir '%s'", argv[i]);
  				puts(gitdir);
  				continue;
  			}
  			if (!strcmp(arg, "--is-inside-git-dir")) {
  				printf("%s\n", is_inside_git_dir() ? "true"
  						: "false");
  				continue;
  			}
  			if (!strcmp(arg, "--is-inside-work-tree")) {
  				printf("%s\n", is_inside_work_tree() ? "true"
  						: "false");
  				continue;
  			}
  			if (!strcmp(arg, "--is-bare-repository")) {
  				printf("%s\n", is_bare_repository() ? "true"
  						: "false");
  				continue;
  			}
  			if (!strcmp(arg, "--shared-index-path")) {
  				if (read_cache() < 0)
  					die(_("Could not read the index"));
  				if (the_index.split_index) {
  					const unsigned char *sha1 = the_index.split_index->base_sha1;
  					puts(git_path("sharedindex.%s", sha1_to_hex(sha1)));
  				}
  				continue;
  			}
  			if (starts_with(arg, "--since=")) {
  				show_datestring("--max-age=", arg+8);
  				continue;
  			}
  			if (starts_with(arg, "--after=")) {
  				show_datestring("--max-age=", arg+8);
  				continue;
  			}
  			if (starts_with(arg, "--before=")) {
  				show_datestring("--min-age=", arg+9);
  				continue;
  			}
  			if (starts_with(arg, "--until=")) {
  				show_datestring("--min-age=", arg+8);
  				continue;
  			}
  			if (show_flag(arg) && verify)
  				die_no_single_rev(quiet);
  			continue;
  		}
  
  		/* Not a flag argument */
  		if (try_difference(arg))
  			continue;
  		if (try_parent_shorthands(arg))
  			continue;
  		name = arg;
  		type = NORMAL;
  		if (*arg == '^') {
  			name++;
  			type = REVERSED;
  		}
  		if (!get_sha1_with_context(name, flags, sha1, &unused)) {
  			if (verify)
  				revs_count++;
  			else
  				show_rev(type, sha1, name);
  			continue;
  		}
  		if (verify)
  			die_no_single_rev(quiet);
  		if (has_dashdash)
  			die("bad revision '%s'", arg);
  		as_is = 1;
  		if (!show_file(arg, output_prefix))
  			continue;
  		verify_filename(prefix, arg, 1);
  	}
  	if (verify) {
  		if (revs_count == 1) {
  			show_rev(type, sha1, name);
  			return 0;
  		} else if (revs_count == 0 && show_default())
  			return 0;
  		die_no_single_rev(quiet);
  	} else
  		show_default();
  	return 0;
  }
  