Merge branch 'jc/lt-ref2-with-lt-refs' into jc/ref-locking

* jc/lt-ref2-with-lt-refs:
  Fix show-ref usage for --dereference.
  Document git-show-ref [-s|--hash] option.
  Add man page for git-show-ref
  gitignore: git-show-ref is a generated file.
  Use Linus' show ref in "git-branch.sh".
  Add [-s|--hash] option to Linus' show-ref.
  Teach "git checkout" to use git-show-ref
  Add "git show-ref" builtin command

1 files changed, 120 insertions, 0 deletions

diff --git a/builtin-show-ref.c b/builtin-show-ref.c
new file mode 100644
index 0000000000..12c457c3c1
--- /dev/null
+++ b/builtin-show-ref.c
@@ -0,0 +1,120 @@
+#include "cache.h"
+#include "refs.h"
+#include "object.h"
+#include "tag.h"
+
+static const char show_ref_usage[] = "git show-ref [-q|--quiet] [--verify] [-h|--head] [-d|--dereference] [-s|--hash] [--tags] [--heads] [--] [pattern*]";
+
+static int deref_tags = 0, show_head = 0, tags_only = 0, heads_only = 0,
+	found_match = 0, verify = 0, quiet = 0, hash_only = 0;
+static const char **pattern;
+
+static int show_ref(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
+{
+	struct object *obj;
+
+	if (tags_only || heads_only) {
+		int match;
+
+		match = heads_only && !strncmp(refname, "refs/heads/", 11);
+		match |= tags_only && !strncmp(refname, "refs/tags/", 10);
+		if (!match)
+			return 0;
+	}
+	if (pattern) {
+		int reflen = strlen(refname);
+		const char **p = pattern, *m;
+		while ((m = *p++) != NULL) {
+			int len = strlen(m);
+			if (len > reflen)
+				continue;
+			if (memcmp(m, refname + reflen - len, len))
+				continue;
+			if (len == reflen)
+				goto match;
+			/* "--verify" requires an exact match */
+			if (verify)
+				continue;
+			if (refname[reflen - len - 1] == '/')
+				goto match;
+		}
+		return 0;
+	}
+
+match:
+	found_match++;
+	obj = parse_object(sha1);
+	if (!obj) {
+		if (quiet)
+			return 0;
+		die("git-show-ref: bad ref %s (%s)", refname, sha1_to_hex(sha1));
+	}
+	if (quiet)
+		return 0;
+	if (hash_only)
+		printf("%s\n", sha1_to_hex(sha1));
+	else
+		printf("%s %s\n", sha1_to_hex(sha1), refname);
+	if (deref_tags && obj->type == OBJ_TAG) {
+		obj = deref_tag(obj, refname, 0);
+		printf("%s %s^{}\n", sha1_to_hex(obj->sha1), refname);
+	}
+	return 0;
+}
+
+int cmd_show_ref(int argc, const char **argv, const char *prefix)
+{
+	int i;
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (*arg != '-') {
+			pattern = argv + i;
+			break;
+		}
+		if (!strcmp(arg, "--")) {
+			pattern = argv + i + 1;
+			if (!*pattern)
+				pattern = NULL;
+			break;
+		}
+		if (!strcmp(arg, "-q") || !strcmp(arg, "--quiet")) {
+			quiet = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-h") || !strcmp(arg, "--head")) {
+			show_head = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-d") || !strcmp(arg, "--dereference")) {
+			deref_tags = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-s") || !strcmp(arg, "--hash")) {
+			hash_only = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--verify")) {
+			verify = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--tags")) {
+			tags_only = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--heads")) {
+			heads_only = 1;
+			continue;
+		}
+		usage(show_ref_usage);
+	}
+	if (show_head)
+		head_ref(show_ref, NULL);
+	for_each_ref(show_ref, NULL);
+	if (!found_match) {
+		if (verify && !quiet)
+			die("No match");
+		return 1;
+	}
+	return 0;
+}