1 files changed, 202 insertions, 98 deletions

diff --git a/builtin/show-ref.c b/builtin/show-ref.c
index 5fa207a..1c15421 100644
--- a/builtin/show-ref.c
+++ b/builtin/show-ref.c
@@ -1,60 +1,79 @@
 #include "builtin.h"
-#include "cache.h"
 #include "config.h"
-#include "refs.h"
-#include "object-store.h"
+#include "gettext.h"
+#include "hex.h"
+#include "refs/refs-internal.h"
+#include "object-name.h"
+#include "object-store-ll.h"
 #include "object.h"
-#include "tag.h"
 #include "string-list.h"
 #include "parse-options.h"
 
 static const char * const show_ref_usage[] = {
-	N_("git show-ref [-q | --quiet] [--verify] [--head] [-d | --dereference] [-s | --hash[=<n>]] [--abbrev[=<n>]] [--tags] [--heads] [--] [<pattern>...]"),
+	N_("git show-ref [--head] [-d | --dereference]\n"
+	   "             [-s | --hash[=<n>]] [--abbrev[=<n>]] [--tags]\n"
+	   "             [--heads] [--] [<pattern>...]"),
+	N_("git show-ref --verify [-q | --quiet] [-d | --dereference]\n"
+	   "             [-s | --hash[=<n>]] [--abbrev[=<n>]]\n"
+	   "             [--] [<ref>...]"),
 	N_("git show-ref --exclude-existing[=<pattern>]"),
+	N_("git show-ref --exists <ref>"),
 	NULL
 };
 
-static int deref_tags, show_head, tags_only, heads_only, found_match, verify,
-	   quiet, hash_only, abbrev, exclude_arg;
-static const char **pattern;
-static const char *exclude_existing_arg;
+struct show_one_options {
+	int quiet;
+	int hash_only;
+	int abbrev;
+	int deref_tags;
+};
 
-static void show_one(const char *refname, const struct object_id *oid)
+static void show_one(const struct show_one_options *opts,
+		     const char *refname, const struct object_id *oid)
 {
 	const char *hex;
 	struct object_id peeled;
 
-	if (!has_object_file(oid))
+	if (!repo_has_object_file(the_repository, oid))
 		die("git show-ref: bad ref %s (%s)", refname,
 		    oid_to_hex(oid));
 
-	if (quiet)
+	if (opts->quiet)
 		return;
 
-	hex = find_unique_abbrev(oid, abbrev);
-	if (hash_only)
+	hex = repo_find_unique_abbrev(the_repository, oid, opts->abbrev);
+	if (opts->hash_only)
 		printf("%s\n", hex);
 	else
 		printf("%s %s\n", hex, refname);
 
-	if (!deref_tags)
+	if (!opts->deref_tags)
 		return;
 
 	if (!peel_iterated_oid(oid, &peeled)) {
-		hex = find_unique_abbrev(&peeled, abbrev);
+		hex = repo_find_unique_abbrev(the_repository, &peeled, opts->abbrev);
 		printf("%s %s^{}\n", hex, refname);
 	}
 }
 
+struct show_ref_data {
+	const struct show_one_options *show_one_opts;
+	const char **patterns;
+	int found_match;
+	int show_head;
+};
+
 static int show_ref(const char *refname, const struct object_id *oid,
-		    int flag, void *cbdata)
+		    int flag UNUSED, void *cbdata)
 {
-	if (show_head && !strcmp(refname, "HEAD"))
+	struct show_ref_data *data = cbdata;
+
+	if (data->show_head && !strcmp(refname, "HEAD"))
 		goto match;
 
-	if (pattern) {
+	if (data->patterns) {
 		int reflen = strlen(refname);
-		const char **p = pattern, *m;
+		const char **p = data->patterns, *m;
 		while ((m = *p++) != NULL) {
 			int len = strlen(m);
 			if (len > reflen)
@@ -70,21 +89,31 @@ static int show_ref(const char *refname, const struct object_id *oid,
 	}
 
 match:
-	found_match++;
+	data->found_match++;
 
-	show_one(refname, oid);
+	show_one(data->show_one_opts, refname, oid);
 
 	return 0;
 }
 
-static int add_existing(const char *refname, const struct object_id *oid,
-			int flag, void *cbdata)
+static int add_existing(const char *refname,
+			const struct object_id *oid UNUSED,
+			int flag UNUSED, void *cbdata)
 {
 	struct string_list *list = (struct string_list *)cbdata;
 	string_list_insert(list, refname);
 	return 0;
 }
 
+struct exclude_existing_options {
+	/*
+	 * We need an explicit `enabled` field because it is perfectly valid
+	 * for `pattern` to be `NULL` even if `--exclude-existing` was given.
+	 */
+	int enabled;
+	const char *pattern;
+};
+
 /*
  * read "^(?:<anything>\s)?<refname>(?:\^\{\})?$" from the standard input,
  * and
@@ -94,11 +123,11 @@ static int add_existing(const char *refname, const struct object_id *oid,
  * (4) ignore if refname is a ref that exists in the local repository;
  * (5) otherwise output the line.
  */
-static int exclude_existing(const char *match)
+static int cmd_show_ref__exclude_existing(const struct exclude_existing_options *opts)
 {
-	static struct string_list existing_refs = STRING_LIST_INIT_DUP;
+	struct string_list existing_refs = STRING_LIST_INIT_DUP;
 	char buf[1024];
-	int matchlen = match ? strlen(match) : 0;
+	int patternlen = opts->pattern ? strlen(opts->pattern) : 0;
 
 	for_each_ref(add_existing, &existing_refs);
 	while (fgets(buf, sizeof(buf), stdin)) {
@@ -114,11 +143,11 @@ static int exclude_existing(const char *match)
 		for (ref = buf + len; buf < ref; ref--)
 			if (isspace(ref[-1]))
 				break;
-		if (match) {
+		if (opts->pattern) {
 			int reflen = buf + len - ref;
-			if (reflen < matchlen)
+			if (reflen < patternlen)
 				continue;
-			if (strncmp(ref, match, matchlen))
+			if (strncmp(ref, opts->pattern, patternlen))
 				continue;
 		}
 		if (check_refname_format(ref, 0)) {
@@ -129,97 +158,172 @@ static int exclude_existing(const char *match)
 			printf("%s\n", buf);
 		}
 	}
+
+	string_list_clear(&existing_refs, 0);
+	return 0;
+}
+
+static int cmd_show_ref__verify(const struct show_one_options *show_one_opts,
+				const char **refs)
+{
+	if (!refs || !*refs)
+		die("--verify requires a reference");
+
+	while (*refs) {
+		struct object_id oid;
+
+		if ((starts_with(*refs, "refs/") || refname_is_safe(*refs)) &&
+		    !read_ref(*refs, &oid)) {
+			show_one(show_one_opts, *refs, &oid);
+		}
+		else if (!show_one_opts->quiet)
+			die("'%s' - not a valid ref", *refs);
+		else
+			return 1;
+		refs++;
+	}
+
 	return 0;
 }
 
+struct patterns_options {
+	int show_head;
+	int heads_only;
+	int tags_only;
+};
+
+static int cmd_show_ref__patterns(const struct patterns_options *opts,
+				  const struct show_one_options *show_one_opts,
+				  const char **patterns)
+{
+	struct show_ref_data show_ref_data = {
+		.show_one_opts = show_one_opts,
+		.show_head = opts->show_head,
+	};
+
+	if (patterns && *patterns)
+		show_ref_data.patterns = patterns;
+
+	if (opts->show_head)
+		head_ref(show_ref, &show_ref_data);
+	if (opts->heads_only || opts->tags_only) {
+		if (opts->heads_only)
+			for_each_fullref_in("refs/heads/", show_ref, &show_ref_data);
+		if (opts->tags_only)
+			for_each_fullref_in("refs/tags/", show_ref, &show_ref_data);
+	} else {
+		for_each_ref(show_ref, &show_ref_data);
+	}
+	if (!show_ref_data.found_match)
+		return 1;
+
+	return 0;
+}
+
+static int cmd_show_ref__exists(const char **refs)
+{
+	struct strbuf unused_referent = STRBUF_INIT;
+	struct object_id unused_oid;
+	unsigned int unused_type;
+	int failure_errno = 0;
+	const char *ref;
+	int ret = 0;
+
+	if (!refs || !*refs)
+		die("--exists requires a reference");
+	ref = *refs++;
+	if (*refs)
+		die("--exists requires exactly one reference");
+
+	if (refs_read_raw_ref(get_main_ref_store(the_repository), ref,
+			      &unused_oid, &unused_referent, &unused_type,
+			      &failure_errno)) {
+		if (failure_errno == ENOENT || failure_errno == EISDIR) {
+			error(_("reference does not exist"));
+			ret = 2;
+		} else {
+			errno = failure_errno;
+			error_errno(_("failed to look up reference"));
+			ret = 1;
+		}
+
+		goto out;
+	}
+
+out:
+	strbuf_release(&unused_referent);
+	return ret;
+}
+
 static int hash_callback(const struct option *opt, const char *arg, int unset)
 {
-	hash_only = 1;
+	struct show_one_options *opts = opt->value;
+	struct option abbrev_opt = *opt;
+
+	opts->hash_only = 1;
 	/* Use full length SHA1 if no argument */
 	if (!arg)
 		return 0;
-	return parse_opt_abbrev_cb(opt, arg, unset);
+
+	abbrev_opt.value = &opts->abbrev;
+	return parse_opt_abbrev_cb(&abbrev_opt, arg, unset);
 }
 
 static int exclude_existing_callback(const struct option *opt, const char *arg,
 				     int unset)
 {
+	struct exclude_existing_options *opts = opt->value;
 	BUG_ON_OPT_NEG(unset);
-	exclude_arg = 1;
-	*(const char **)opt->value = arg;
+	opts->enabled = 1;
+	opts->pattern = arg;
 	return 0;
 }
 
-static const struct option show_ref_options[] = {
-	OPT_BOOL(0, "tags", &tags_only, N_("only show tags (can be combined with heads)")),
-	OPT_BOOL(0, "heads", &heads_only, N_("only show heads (can be combined with tags)")),
-	OPT_BOOL(0, "verify", &verify, N_("stricter reference checking, "
-		    "requires exact ref path")),
-	OPT_HIDDEN_BOOL('h', NULL, &show_head,
-			N_("show the HEAD reference, even if it would be filtered out")),
-	OPT_BOOL(0, "head", &show_head,
-	  N_("show the HEAD reference, even if it would be filtered out")),
-	OPT_BOOL('d', "dereference", &deref_tags,
-		    N_("dereference tags into object IDs")),
-	OPT_CALLBACK_F('s', "hash", &abbrev, N_("n"),
-		       N_("only show SHA1 hash using <n> digits"),
-		       PARSE_OPT_OPTARG, &hash_callback),
-	OPT__ABBREV(&abbrev),
-	OPT__QUIET(&quiet,
-		   N_("do not print results to stdout (useful with --verify)")),
-	OPT_CALLBACK_F(0, "exclude-existing", &exclude_existing_arg,
-		       N_("pattern"), N_("show refs from stdin that aren't in local repository"),
-		       PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback),
-	OPT_END()
-};
-
 int cmd_show_ref(int argc, const char **argv, const char *prefix)
 {
+	struct exclude_existing_options exclude_existing_opts = {0};
+	struct patterns_options patterns_opts = {0};
+	struct show_one_options show_one_opts = {0};
+	int verify = 0, exists = 0;
+	const struct option show_ref_options[] = {
+		OPT_BOOL(0, "tags", &patterns_opts.tags_only, N_("only show tags (can be combined with heads)")),
+		OPT_BOOL(0, "heads", &patterns_opts.heads_only, N_("only show heads (can be combined with tags)")),
+		OPT_BOOL(0, "exists", &exists, N_("check for reference existence without resolving")),
+		OPT_BOOL(0, "verify", &verify, N_("stricter reference checking, "
+			    "requires exact ref path")),
+		OPT_HIDDEN_BOOL('h', NULL, &patterns_opts.show_head,
+				N_("show the HEAD reference, even if it would be filtered out")),
+		OPT_BOOL(0, "head", &patterns_opts.show_head,
+		  N_("show the HEAD reference, even if it would be filtered out")),
+		OPT_BOOL('d', "dereference", &show_one_opts.deref_tags,
+			    N_("dereference tags into object IDs")),
+		OPT_CALLBACK_F('s', "hash", &show_one_opts, N_("n"),
+			       N_("only show SHA1 hash using <n> digits"),
+			       PARSE_OPT_OPTARG, &hash_callback),
+		OPT__ABBREV(&show_one_opts.abbrev),
+		OPT__QUIET(&show_one_opts.quiet,
+			   N_("do not print results to stdout (useful with --verify)")),
+		OPT_CALLBACK_F(0, "exclude-existing", &exclude_existing_opts,
+			       N_("pattern"), N_("show refs from stdin that aren't in local repository"),
+			       PARSE_OPT_OPTARG | PARSE_OPT_NONEG, exclude_existing_callback),
+		OPT_END()
+	};
+
 	git_config(git_default_config, NULL);
 
 	argc = parse_options(argc, argv, prefix, show_ref_options,
 			     show_ref_usage, 0);
 
-	if (exclude_arg)
-		return exclude_existing(exclude_existing_arg);
-
-	pattern = argv;
-	if (!*pattern)
-		pattern = NULL;
-
-	if (verify) {
-		if (!pattern)
-			die("--verify requires a reference");
-		while (*pattern) {
-			struct object_id oid;
-
-			if ((starts_with(*pattern, "refs/") || !strcmp(*pattern, "HEAD")) &&
-			    !read_ref(*pattern, &oid)) {
-				show_one(*pattern, &oid);
-			}
-			else if (!quiet)
-				die("'%s' - not a valid ref", *pattern);
-			else
-				return 1;
-			pattern++;
-		}
-		return 0;
-	}
+	die_for_incompatible_opt3(exclude_existing_opts.enabled, "--exclude-existing",
+				  verify, "--verify",
+				  exists, "--exists");
 
-	if (show_head)
-		head_ref(show_ref, NULL);
-	if (heads_only || tags_only) {
-		if (heads_only)
-			for_each_fullref_in("refs/heads/", show_ref, NULL);
-		if (tags_only)
-			for_each_fullref_in("refs/tags/", show_ref, NULL);
-	} else {
-		for_each_ref(show_ref, NULL);
-	}
-	if (!found_match) {
-		if (verify && !quiet)
-			die("No match");
-		return 1;
-	}
-	return 0;
+	if (exclude_existing_opts.enabled)
+		return cmd_show_ref__exclude_existing(&exclude_existing_opts);
+	else if (verify)
+		return cmd_show_ref__verify(&show_one_opts, argv);
+	else if (exists)
+		return cmd_show_ref__exists(argv);
+	else
+		return cmd_show_ref__patterns(&patterns_opts, &show_one_opts, argv);
 }