Merge branch 'lj/refs'

* lj/refs: (63 commits)
  Fix show-ref usagestring
  t3200: git-branch testsuite update
  sha1_name.c: avoid compilation warnings.
  Make git-branch a builtin
  ref-log: fix D/F conflict coming from deleted refs.
  git-revert with conflicts to behave as git-merge with conflicts
  core.logallrefupdates thinko-fix
  git-pack-refs --all
  core.logallrefupdates create new log file only for branch heads.
  Remove bashism from t3210-pack-refs.sh
  ref-log: allow ref@{count} syntax.
  pack-refs: call fflush before fsync.
  pack-refs: use lockfile as everybody else does.
  git-fetch: do not look into $GIT_DIR/refs to see if a tag exists.
  lock_ref_sha1_basic does not remove empty directories on BSD
  Do not create tag leading directories since git update-ref does it.
  Check that a tag exists using show-ref instead of looking for the ref file.
  Use git-update-ref to delete a tag instead of rm()ing the ref file.
  Fix refs.c;:repack_without_ref() clean-up path
  Clean up "git-branch.sh" and add remove recursive dir test cases.
  ...

.gitignore

@@ -75,6 +75,7 @@ git-name-rev
 git-mv
 git-pack-redundant
 git-pack-objects
+git-pack-refs
 git-parse-remote
 git-patch-id
 git-peek-remote
@@ -106,6 +107,7 @@ git-shortlog
 git-show
 git-show-branch
 git-show-index
+git-show-ref
 git-ssh-fetch
 git-ssh-pull
 git-ssh-push

Documentation/config.txt

@@ -71,12 +71,16 @@ core.preferSymlinkRefs::
 	expect HEAD to be a symbolic link.
 
 core.logAllRefUpdates::
-	If true, `git-update-ref` will append a line to
-	"$GIT_DIR/logs/<ref>" listing the new SHA1 and the date/time
-	of the update.	If the file does not exist it will be
-	created automatically.	This information can be used to
-	determine what commit was the tip of a branch "2 days ago".
-	This value is false by default (no logging).
+	Updates to a ref <ref> is logged to the file
+	"$GIT_DIR/logs/<ref>", by appending the new and old
+	SHA1, the date/time and the reason of the update, but
+	only when the file exists.  If this configuration
+	variable is set to true, missing "$GIT_DIR/logs/<ref>"
+	file is automatically created for branch heads.
+
+	This information can be used to determine what commit
+	was the tip of a branch "2 days ago".  This value is
+	false by default (no automated creation of log files).
 
 core.repositoryFormatVersion::
 	Internal variable identifying the repository format and layout

Documentation/git-show-ref.txt

+git-show-ref(1)
+===============
+
+NAME
+----
+git-show-ref - List references in a local repository
+
+SYNOPSIS
+--------
+[verse]
+'git-show-ref' [-q|--quiet] [--verify] [-h|--head] [-d|--dereference]
+	     [-s|--hash] [--abbrev] [--tags] [--heads] [--] <pattern>...
+
+DESCRIPTION
+-----------
+
+Displays references available in a local repository along with the associated
+commit IDs. Results can be filtered using a pattern and tags can be
+dereferenced into object IDs. Additionally, it can be used to test whether a
+particular ref exists.
+
+Use of this utility is encouraged in favor of directly accessing files under
+in the `.git` directory.
+
+OPTIONS
+-------
+
+-h, --head::
+
+	Show the HEAD reference.
+
+--tags, --heads::
+
+	Limit to only "refs/heads" and "refs/tags", respectively.  These
+	options are not mutually exclusive; when given both, references stored
+	in "refs/heads" and "refs/tags" are displayed.
+
+-d, --dereference::
+
+	Dereference tags into object IDs as well. They will be shown with "^{}"
+	appended.
+
+-s, --hash::
+
+	Only show the SHA1 hash, not the reference name. When also using
+	--dereference the dereferenced tag will still be shown after the SHA1.
+
+--verify::
+
+	Enable stricter reference checking by requiring an exact ref path.
+	Aside from returning an error code of 1, it will also print an error
+	message if '--quiet' was not specified.
+
+--abbrev, --abbrev=len::
+
+	Abbreviate the object name.  When using `--hash`, you do
+	not have to say `--hash --abbrev`; `--hash=len` would do.
+
+-q, --quiet::
+
+	Do not print any results to stdout. When combined with '--verify' this
+	can be used to silently check if a reference exists.
+
+<pattern>::
+
+	Show references matching one or more patterns.
+
+OUTPUT
+------
+
+The output is in the format: '<SHA-1 ID>' '<space>' '<reference name>'.
+
+-----------------------------------------------------------------------------
+$ git show-ref --head --dereference
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 HEAD
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/master
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/origin
+3521017556c5de4159da4615a39fa4d5d2c279b5 refs/tags/v0.99.9c
+6ddc0964034342519a87fe013781abf31c6db6ad refs/tags/v0.99.9c^{}
+055e4ae3ae6eb344cbabf2a5256a49ea66040131 refs/tags/v1.0rc4
+423325a2d24638ddcc82ce47be5e40be550f4507 refs/tags/v1.0rc4^{}
+...
+-----------------------------------------------------------------------------
+
+When using --hash (and not --dereference) the output format is: '<SHA-1 ID>'
+
+-----------------------------------------------------------------------------
+$ git show-ref --heads --hash
+2e3ba0114a1f52b47df29743d6915d056be13278
+185008ae97960c8d551adcd9e23565194651b5d1
+03adf42c988195b50e1a1935ba5fcbc39b2b029b
+...
+-----------------------------------------------------------------------------
+
+EXAMPLE
+-------
+
+To show all references called "master", whether tags or heads or anything
+else, and regardless of how deep in the reference naming hierarchy they are,
+use:
+
+-----------------------------------------------------------------------------
+	git show-ref master
+-----------------------------------------------------------------------------
+
+This will show "refs/heads/master" but also "refs/remote/other-repo/master",
+if such references exists.
+
+When using the '--verify' flag, the command requires an exact path:
+
+-----------------------------------------------------------------------------
+	git show-ref --verify refs/heads/master
+-----------------------------------------------------------------------------
+
+will only match the exact branch called "master".
+
+If nothing matches, gitlink:git-show-ref[1] will return an error code of 1,
+and in the case of verification, it will show an error message.
+
+For scripting, you can ask it to be quiet with the "--quiet" flag, which
+allows you to do things like
+
+-----------------------------------------------------------------------------
+	git-show-ref --quiet --verify -- "refs/heads/$headname" ||
+		echo "$headname is not a valid branch"
+-----------------------------------------------------------------------------
+
+to check whether a particular branch exists or not (notice how we don't
+actually want to show any results, and we want to use the full refname for it
+in order to not trigger the problem with ambiguous partial matches).
+
+To show only tags, or only proper branch heads, use "--tags" and/or "--heads"
+respectively (using both means that it shows tags and heads, but not other
+random references under the refs/ subdirectory).
+
+To do automatic tag object dereferencing, use the "-d" or "--dereference"
+flag, so you can do
+
+-----------------------------------------------------------------------------
+	git show-ref --tags --dereference
+-----------------------------------------------------------------------------
+
+to get a listing of all tags together with what they dereference.
+
+SEE ALSO
+--------
+gitlink:git-ls-remote[1], gitlink:git-peek-remote[1]
+
+AUTHORS
+-------
+Written by Linus Torvalds <torvalds@osdl.org>.
+Man page by Jonas Fonseca <fonseca@diku.dk>.
+
+GIT
+---
+Part of the gitlink:git[7] suite

Documentation/git-update-ref.txt

@@ -7,7 +7,7 @@ git-update-ref - update the object name stored in a ref safely
 
 SYNOPSIS
 --------
-'git-update-ref' [-m <reason>] <ref> <newvalue> [<oldvalue>]
+'git-update-ref' [-m <reason>] (-d <ref> <oldvalue> | <ref> <newvalue> [<oldvalue>])
 
 DESCRIPTION
 -----------
@@ -20,7 +20,9 @@ possibly dereferencing the symbolic refs, after verifying that
 the current value of the <ref> matches <oldvalue>.
 E.g. `git-update-ref refs/heads/master <newvalue> <oldvalue>`
 updates the master branch head to <newvalue> only if its current
-value is <oldvalue>.
+value is <oldvalue>.  You can specify 40 "0" or an empty string
+as <oldvalue> to make sure that the ref you are creating does
+not exist.
 
 It also allows a "ref" file to be a symbolic pointer to another
 ref file by starting with the four-byte header sequence of
@@ -49,6 +51,10 @@ for reading but not for writing (so we'll never write through a
 ref symlink to some other tree, if you have copied a whole
 archive by creating a symlink tree).
 
+With `-d` flag, it deletes the named <ref> after verifying it
+still contains <oldvalue>.
+
+
 Logging Updates
 ---------------
 If config parameter "core.logAllRefUpdates" is true or the file

Makefile

@@ -158,7 +158,7 @@ BASIC_CFLAGS =
 BASIC_LDFLAGS =
 
 SCRIPT_SH = \
-	git-bisect.sh git-branch.sh git-checkout.sh \
+	git-bisect.sh git-checkout.sh \
 	git-cherry.sh git-clean.sh git-clone.sh git-commit.sh \
 	git-fetch.sh \
 	git-ls-remote.sh \
@@ -270,6 +270,7 @@ BUILTIN_OBJS = \
 	builtin-annotate.o \
 	builtin-apply.o \
 	builtin-archive.o \
+	builtin-branch.o \
 	builtin-cat-file.o \
 	builtin-checkout-index.o \
 	builtin-check-ref-format.o \
@@ -310,7 +311,9 @@ BUILTIN_OBJS = \
 	builtin-update-ref.o \
 	builtin-upload-archive.o \
 	builtin-verify-pack.o \
-	builtin-write-tree.o
+	builtin-write-tree.o \
+	builtin-show-ref.o \
+	builtin-pack-refs.o
 
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
 EXTLIBS = -lz

builtin-branch.c

+/*
+ * Builtin "git branch"
+ *
+ * Copyright (c) 2006 Kristian Hgsberg <krh@redhat.com>
+ * Based on git-branch.sh by Junio C Hamano.
+ */
+
+#include "cache.h"
+#include "refs.h"
+#include "commit.h"
+#include "builtin.h"
+
+static const char builtin_branch_usage[] =
+"git-branch (-d | -D) <branchname> | [-l] [-f] <branchname> [<start-point>] | [-r]";
+
+
+static const char *head;
+static unsigned char head_sha1[20];
+
+static int in_merge_bases(const unsigned char *sha1,
+			  struct commit *rev1,
+			  struct commit *rev2)
+{
+	struct commit_list *bases, *b;
+	int ret = 0;
+
+	bases = get_merge_bases(rev1, rev2, 1);
+	for (b = bases; b; b = b->next) {
+		if (!hashcmp(sha1, b->item->object.sha1)) {
+			ret = 1;
+			break;
+		}
+	}
+
+	free_commit_list(bases);
+	return ret;
+}
+
+static void delete_branches(int argc, const char **argv, int force)
+{
+	struct commit *rev, *head_rev;
+	unsigned char sha1[20];
+	char *name;
+	int i;
+
+	head_rev = lookup_commit_reference(head_sha1);
+	for (i = 0; i < argc; i++) {
+		if (!strcmp(head, argv[i]))
+			die("Cannot delete the branch you are currently on.");
+
+		name = xstrdup(mkpath("refs/heads/%s", argv[i]));
+		if (!resolve_ref(name, sha1, 1, NULL))
+			die("Branch '%s' not found.", argv[i]);
+
+		rev = lookup_commit_reference(sha1);
+		if (!rev || !head_rev)
+			die("Couldn't look up commit objects.");
+
+		/* This checks whether the merge bases of branch and
+		 * HEAD contains branch -- which means that the HEAD
+		 * contains everything in both.
+		 */
+
+		if (!force &&
+		    !in_merge_bases(sha1, rev, head_rev)) {
+			fprintf(stderr,
+				"The branch '%s' is not a strict subset of your current HEAD.\n"
+				"If you are sure you want to delete it, run 'git branch -D %s'.\n",
+				argv[i], argv[i]);
+			exit(1);
+		}
+
+		if (delete_ref(name, sha1))
+			printf("Error deleting branch '%s'\n", argv[i]);
+		else
+			printf("Deleted branch %s.\n", argv[i]);
+
+		free(name);
+	}
+}
+
+static int ref_index, ref_alloc;
+static char **ref_list;
+
+static int append_ref(const char *refname, const unsigned char *sha1, int flags,
+		void *cb_data)
+{
+	if (ref_index >= ref_alloc) {
+		ref_alloc = alloc_nr(ref_alloc);
+		ref_list = xrealloc(ref_list, ref_alloc * sizeof(char *));
+	}
+
+	ref_list[ref_index++] = xstrdup(refname);
+
+	return 0;
+}
+
+static int ref_cmp(const void *r1, const void *r2)
+{
+	return strcmp(*(char **)r1, *(char **)r2);
+}
+
+static void print_ref_list(int remote_only)
+{
+	int i;
+
+	if (remote_only)
+		for_each_remote_ref(append_ref, NULL);
+	else
+		for_each_branch_ref(append_ref, NULL);
+
+	qsort(ref_list, ref_index, sizeof(char *), ref_cmp);
+
+	for (i = 0; i < ref_index; i++) {
+		if (!strcmp(ref_list[i], head))
+			printf("* %s\n", ref_list[i]);
+		else
+			printf("  %s\n", ref_list[i]);
+	}
+}
+
+static void create_branch(const char *name, const char *start,
+			  int force, int reflog)
+{
+	struct ref_lock *lock;
+	struct commit *commit;
+	unsigned char sha1[20];
+	char ref[PATH_MAX], msg[PATH_MAX + 20];
+
+	snprintf(ref, sizeof ref, "refs/heads/%s", name);
+	if (check_ref_format(ref))
+		die("'%s' is not a valid branch name.", name);
+
+	if (resolve_ref(ref, sha1, 1, NULL)) {
+		if (!force)
+			die("A branch named '%s' already exists.", name);
+		else if (!strcmp(head, name))
+			die("Cannot force update the current branch.");
+	}
+
+	if (get_sha1(start, sha1) ||
+	    (commit = lookup_commit_reference(sha1)) == NULL)
+		die("Not a valid branch point: '%s'.", start);
+	hashcpy(sha1, commit->object.sha1);
+
+	lock = lock_any_ref_for_update(ref, NULL);
+	if (!lock)
+		die("Failed to lock ref for update: %s.", strerror(errno));
+
+	if (reflog) {
+		log_all_ref_updates = 1;
+		snprintf(msg, sizeof msg, "branch: Created from %s", start);
+	}
+
+	if (write_ref_sha1(lock, sha1, msg) < 0)
+		die("Failed to write ref: %s.", strerror(errno));
+}
+
+int cmd_branch(int argc, const char **argv, const char *prefix)
+{
+	int delete = 0, force_delete = 0, force_create = 0, remote_only = 0;
+	int reflog = 0;
+	int i;
+
+	git_config(git_default_config);
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (arg[0] != '-')
+			break;
+		if (!strcmp(arg, "--")) {
+			i++;
+			break;
+		}
+		if (!strcmp(arg, "-d")) {
+			delete = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-D")) {
+			delete = 1;
+			force_delete = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-f")) {
+			force_create = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-r")) {
+			remote_only = 1;
+			continue;
+		}
+		if (!strcmp(arg, "-l")) {
+			reflog = 1;
+			continue;
+		}
+		usage(builtin_branch_usage);
+	}
+
+	head = xstrdup(resolve_ref("HEAD", head_sha1, 0, NULL));
+	if (!head)
+		die("Failed to resolve HEAD as a valid ref.");
+	if (strncmp(head, "refs/heads/", 11))
+		die("HEAD not found below refs/heads!");
+	head += 11;
+
+	if (delete)
+		delete_branches(argc - i, argv + i, force_delete);
+	else if (i == argc)
+		print_ref_list(remote_only);
+	else if (i == argc - 1)
+		create_branch(argv[i], head, force_create, reflog);
+	else if (i == argc - 2)
+		create_branch(argv[i], argv[i + 1], force_create, reflog);
+	else
+		usage(builtin_branch_usage);
+
+	return 0;
+}

builtin-fmt-merge-msg.c

@@ -249,7 +249,7 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 	FILE *in = stdin;
 	const char *sep = "";
 	unsigned char head_sha1[20];
-	const char *head, *current_branch;
+	const char *current_branch;
 
 	git_config(fmt_merge_msg_config);
 
@@ -277,10 +277,7 @@ int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 		usage(fmt_merge_msg_usage);
 
 	/* get current branch */
-	head = xstrdup(git_path("HEAD"));
-	current_branch = resolve_ref(head, head_sha1, 1);
-	current_branch += strlen(head) - 4;
-	free((char *)head);
+	current_branch = resolve_ref("HEAD", head_sha1, 1, NULL);
 	if (!strncmp(current_branch, "refs/heads/", 11))
 		current_branch += 11;
 

builtin-for-each-ref.c

@@ -585,24 +585,27 @@ static void get_value(struct refinfo *ref, int atom, struct atom_value **v)
 	*v = &ref->value[atom];
 }
 
-static struct refinfo **grab_array;
-static const char **grab_pattern;
-static int *grab_cnt;
+struct grab_ref_cbdata {
+	struct refinfo **grab_array;
+	const char **grab_pattern;
+	int grab_cnt;
+};
 
 /*
  * A call-back given to for_each_ref().  It is unfortunate that we
  * need to use global variables to pass extra information to this
  * function.
  */
-static int grab_single_ref(const char *refname, const unsigned char *sha1)
+static int grab_single_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
+	struct grab_ref_cbdata *cb = cb_data;
 	struct refinfo *ref;
 	int cnt;
 
-	if (*grab_pattern) {
+	if (*cb->grab_pattern) {
 		const char **pattern;
 		int namelen = strlen(refname);
-		for (pattern = grab_pattern; *pattern; pattern++) {
+		for (pattern = cb->grab_pattern; *pattern; pattern++) {
 			const char *p = *pattern;
 			int plen = strlen(p);
 
@@ -626,25 +629,14 @@ static int grab_single_ref(const char *refname, const unsigned char *sha1)
 	ref->refname = xstrdup(refname);
 	hashcpy(ref->objectname, sha1);
 
-	cnt = *grab_cnt;
-	grab_array = xrealloc(grab_array, sizeof(*grab_array) * (cnt + 1));
-	grab_array[cnt++] = ref;
-	*grab_cnt = cnt;
+	cnt = cb->grab_cnt;
+	cb->grab_array = xrealloc(cb->grab_array,
+				  sizeof(*cb->grab_array) * (cnt + 1));
+	cb->grab_array[cnt++] = ref;
+	cb->grab_cnt = cnt;
 	return 0;
 }
 
-static struct refinfo **grab_refs(const char **pattern, int *cnt)
-{
-	/* Sheesh, we really should make for-each-ref to take
-	 * callback data.
-	 */
-	*cnt = 0;
-	grab_pattern = pattern;
-	grab_cnt = cnt;
-	for_each_ref(grab_single_ref);
-	return grab_array;
-}
-
 static int cmp_ref_sort(struct ref_sort *s, struct refinfo *a, struct refinfo *b)
 {
 	struct atom_value *va, *vb;
@@ -784,6 +776,7 @@ int cmd_for_each_ref(int ac, const char **av, char *prefix)
 	int maxcount = 0;
 	int quote_style = -1; /* unspecified yet */
 	struct refinfo **refs;
+	struct grab_ref_cbdata cbdata;
 
 	for (i = 1; i < ac; i++) {
 		const char *arg = av[i];
@@ -855,7 +848,11 @@ int cmd_for_each_ref(int ac, const char **av, char *prefix)
 
 	verify_format(format);
 
-	refs = grab_refs(av + i, &num_refs);
+	memset(&cbdata, 0, sizeof(cbdata));
+	cbdata.grab_pattern = av + i;
+	for_each_ref(grab_single_ref, &cbdata);
+	refs = cbdata.grab_array;
+	num_refs = cbdata.grab_cnt;
 
 	for (i = 0; i < used_atom_cnt; i++) {
 		if (used_atom[i][0] == '*') {

builtin-init-db.c

@@ -218,8 +218,8 @@ static void create_default_files(const char *git_dir, const char *template_path)
 	 * branch, if it does not exist yet.
 	 */
 	strcpy(path + len, "HEAD");
-	if (read_ref(path, sha1) < 0) {
-		if (create_symref(path, "refs/heads/master") < 0)
+	if (read_ref("HEAD", sha1) < 0) {
+		if (create_symref("HEAD", "refs/heads/master") < 0)
 			exit(1);
 	}
 

builtin-name-rev.c

@@ -75,11 +75,10 @@ static void name_rev(struct commit *commit,
 	}
 }
 
-static int tags_only;
-
-static int name_ref(const char *path, const unsigned char *sha1)
+static int name_ref(const char *path, const unsigned char *sha1, int flags, void *cb_data)
 {
 	struct object *o = parse_object(sha1);
+	int tags_only = *(int*)cb_data;
 	int deref = 0;
 
 	if (tags_only && strncmp(path, "refs/tags/", 10))
@@ -131,6 +130,7 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
 {
 	struct object_array revs = { 0, 0, NULL };
 	int as_is = 0, all = 0, transform_stdin = 0;
+	int tags_only = 0;
 
 	git_config(git_default_config);
 
@@ -186,7 +186,7 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
 		add_object_array((struct object *)commit, *argv, &revs);
 	}
 
-	for_each_ref(name_ref);
+	for_each_ref(name_ref, &tags_only);
 
 	if (transform_stdin) {
 		char buffer[2048];

builtin-pack-refs.c

+#include "cache.h"
+#include "refs.h"
+
+static const char builtin_pack_refs_usage[] =
+"git-pack-refs [--all] [--prune]";
+
+struct ref_to_prune {
+	struct ref_to_prune *next;
+	unsigned char sha1[20];
+	char name[FLEX_ARRAY];
+};
+
+struct pack_refs_cb_data {
+	int prune;
+	struct ref_to_prune *ref_to_prune;
+	FILE *refs_file;
+};
+
+static int do_not_prune(int flags)
+{
+	/* If it is already packed or if it is a symref,
+	 * do not prune it.
+	 */
+	return (flags & (REF_ISSYMREF|REF_ISPACKED));
+}
+
+static int handle_one_ref(const char *path, const unsigned char *sha1,
+			  int flags, void *cb_data)
+{
+	struct pack_refs_cb_data *cb = cb_data;
+
+	/* Do not pack the symbolic refs */
+	if (!(flags & REF_ISSYMREF))
+		fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
+	if (cb->prune && !do_not_prune(flags)) {
+		int namelen = strlen(path) + 1;
+		struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
+		hashcpy(n->sha1, sha1);
+		strcpy(n->name, path);
+		n->next = cb->ref_to_prune;
+		cb->ref_to_prune = n;
+	}
+	return 0;
+}
+
+/* make sure nobody touched the ref, and unlink */
+static void prune_ref(struct ref_to_prune *r)
+{
+	struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
+
+	if (lock) {
+		unlink(git_path("%s", r->name));
+		unlock_ref(lock);
+	}
+}
+
+static void prune_refs(struct ref_to_prune *r)
+{
+	while (r) {
+		prune_ref(r);
+		r = r->next;
+	}
+}
+
+static struct lock_file packed;
+
+int cmd_pack_refs(int argc, const char **argv, const char *prefix)
+{
+	int fd, i;
+	struct pack_refs_cb_data cbdata;
+	int (*iterate_ref)(each_ref_fn, void *) = for_each_tag_ref;
+
+	memset(&cbdata, 0, sizeof(cbdata));
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "--prune")) {
+			cbdata.prune = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--all")) {
+			iterate_ref = for_each_ref;
+			continue;
+		}
+		/* perhaps other parameters later... */
+		break;
+	}
+	if (i != argc)
+		usage(builtin_pack_refs_usage);
+
+	fd = hold_lock_file_for_update(&packed, git_path("packed-refs"), 1);
+	cbdata.refs_file = fdopen(fd, "w");
+	if (!cbdata.refs_file)
+		die("unable to create ref-pack file structure (%s)",
+		    strerror(errno));
+	iterate_ref(handle_one_ref, &cbdata);
+	fflush(cbdata.refs_file);
+	fsync(fd);
+	fclose(cbdata.refs_file);
+	if (commit_lock_file(&packed) < 0)
+		die("unable to overwrite old ref-pack file (%s)", strerror(errno));
+	if (cbdata.prune)
+		prune_refs(cbdata.ref_to_prune);
+	return 0;
+}

builtin-prune.c

@@ -174,7 +174,7 @@ static void walk_commit_list(struct rev_info *revs)
 	}
 }
 
-static int add_one_ref(const char *path, const unsigned char *sha1)
+static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *object = parse_object(sha1);
 	if (!object)
@@ -240,7 +240,7 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 	revs.tree_objects = 1;
 
 	/* Add all external refs */
-	for_each_ref(add_one_ref);
+	for_each_ref(add_one_ref, NULL);
 
 	/* Add all refs from the index file */
 	add_cache_refs();

builtin-push.c

@@ -27,7 +27,7 @@ static void add_refspec(const char *ref)
 	refspec_nr = nr;
 }
 
-static int expand_one_ref(const char *ref, const unsigned char *sha1)
+static int expand_one_ref(const char *ref, const unsigned char *sha1, int flag, void *cb_data)
 {
 	/* Ignore the "refs/" at the beginning of the refname */
 	ref += 5;
@@ -51,7 +51,7 @@ static void expand_refspecs(void)
 	}
 	if (!tags)
 		return;
-	for_each_ref(expand_one_ref);
+	for_each_ref(expand_one_ref, NULL);
 }
 
 static void set_refspecs(const char **refs, int nr)

builtin-rev-parse.c

@@ -137,7 +137,7 @@ static void show_default(void)
 	}
 }
 
-static int show_reference(const char *refname, const unsigned char *sha1)
+static int show_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	show_rev(NORMAL, sha1, refname);
 	return 0;
@@ -299,19 +299,19 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				continue;
 			}
 			if (!strcmp(arg, "--all")) {
-				for_each_ref(show_reference);
+				for_each_ref(show_reference, NULL);
 				continue;
 			}
 			if (!strcmp(arg, "--branches")) {
-				for_each_branch_ref(show_reference);
+				for_each_branch_ref(show_reference, NULL);
 				continue;
 			}
 			if (!strcmp(arg, "--tags")) {
-				for_each_tag_ref(show_reference);
+				for_each_tag_ref(show_reference, NULL);
 				continue;
 			}
 			if (!strcmp(arg, "--remotes")) {
-				for_each_remote_ref(show_reference);
+				for_each_remote_ref(show_reference, NULL);
 				continue;
 			}
 			if (!strcmp(arg, "--show-prefix")) {

builtin-show-branch.c

@@ -346,7 +346,7 @@ static void sort_ref_range(int bottom, int top)
 	      compare_ref_name);
 }
 
-static int append_ref(const char *refname, const unsigned char *sha1)
+static int append_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 	int i;
@@ -369,7 +369,7 @@ static int append_ref(const char *refname, const unsigned char *sha1)
 	return 0;
 }
 
-static int append_head_ref(const char *refname, const unsigned char *sha1)
+static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	unsigned char tmp[20];
 	int ofs = 11;
@@ -380,14 +380,14 @@ static int append_head_ref(const char *refname, const unsigned char *sha1)
 	 */
 	if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 		ofs = 5;
-	return append_ref(refname + ofs, sha1);
+	return append_ref(refname + ofs, sha1, flag, cb_data);
 }
 
-static int append_tag_ref(const char *refname, const unsigned char *sha1)
+static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	if (strncmp(refname, "refs/tags/", 10))
 		return 0;
-	return append_ref(refname + 5, sha1);
+	return append_ref(refname + 5, sha1, flag, cb_data);
 }
 
 static const char *match_ref_pattern = NULL;
@@ -401,7 +401,7 @@ static int count_slash(const char *s)
 	return cnt;
 }
 
-static int append_matching_ref(const char *refname, const unsigned char *sha1)
+static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	/* we want to allow pattern hold/<asterisk> to show all
 	 * branches under refs/heads/hold/, and v0.99.9? to show
@@ -417,41 +417,39 @@ static int append_matching_ref(const char *refname, const unsigned char *sha1)
 	if (fnmatch(match_ref_pattern, tail, 0))
 		return 0;
 	if (!strncmp("refs/heads/", refname, 11))
-		return append_head_ref(refname, sha1);
+		return append_head_ref(refname, sha1, flag, cb_data);
 	if (!strncmp("refs/tags/", refname, 10))
-		return append_tag_ref(refname, sha1);
-	return append_ref(refname, sha1);
+		return append_tag_ref(refname, sha1, flag, cb_data);
+	return append_ref(refname, sha1, flag, cb_data);
 }
 
 static void snarf_refs(int head, int tag)
 {
 	if (head) {
 		int orig_cnt = ref_name_cnt;
-		for_each_ref(append_head_ref);
+		for_each_ref(append_head_ref, NULL);
 		sort_ref_range(orig_cnt, ref_name_cnt);
 	}
 	if (tag) {
 		int orig_cnt = ref_name_cnt;
-		for_each_ref(append_tag_ref);
+		for_each_ref(append_tag_ref, NULL);
 		sort_ref_range(orig_cnt, ref_name_cnt);
 	}
 }
 
-static int rev_is_head(char *head_path, int headlen, char *name,
+static int rev_is_head(char *head, int headlen, char *name,
 		       unsigned char *head_sha1, unsigned char *sha1)
 {
-	int namelen;
-	if ((!head_path[0]) ||
+	if ((!head[0]) ||
 	    (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 		return 0;
-	namelen = strlen(name);
-	if ((headlen < namelen) ||
-	    memcmp(head_path + headlen - namelen, name, namelen))
-		return 0;
-	if (headlen == namelen ||
-	    head_path[headlen - namelen - 1] == '/')
-		return 1;
-	return 0;
+	if (!strncmp(head, "refs/heads/", 11))
+		head += 11;
+	if (!strncmp(name, "refs/heads/", 11))
+		name += 11;
+	else if (!strncmp(name, "heads/", 6))
+		name += 6;
+	return !strcmp(head, name);
 }
 
 static int show_merge_base(struct commit_list *seen, int num_rev)
@@ -495,7 +493,7 @@ static void append_one_rev(const char *av)
 {
 	unsigned char revkey[20];
 	if (!get_sha1(av, revkey)) {
-		append_ref(av, revkey);
+		append_ref(av, revkey, 0, NULL);
 		return;
 	}
 	if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
@@ -503,7 +501,7 @@ static void append_one_rev(const char *av)
 		int saved_matches = ref_name_cnt;
 		match_ref_pattern = av;
 		match_ref_slash = count_slash(av);
-		for_each_ref(append_matching_ref);
+		for_each_ref(append_matching_ref, NULL);
 		if (saved_matches == ref_name_cnt &&
 		    ref_name_cnt < MAX_REVS)
 			error("no matching refs with %s", av);
@@ -559,9 +557,9 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 	int all_heads = 0, all_tags = 0;
 	int all_mask, all_revs;
 	int lifo = 1;
-	char head_path[128];
-	const char *head_path_p;
-	int head_path_len;
+	char head[128];
+	const char *head_p;
+	int head_len;
 	unsigned char head_sha1[20];
 	int merge_base = 0;
 	int independent = 0;
@@ -638,31 +636,31 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 		ac--; av++;
 	}
 
-	head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
-	if (head_path_p) {
-		head_path_len = strlen(head_path_p);
-		memcpy(head_path, head_path_p, head_path_len + 1);
+	head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
+	if (head_p) {
+		head_len = strlen(head_p);
+		memcpy(head, head_p, head_len + 1);
 	}
 	else {
-		head_path_len = 0;
-		head_path[0] = 0;
+		head_len = 0;
+		head[0] = 0;
 	}
 
-	if (with_current_branch && head_path_p) {
+	if (with_current_branch && head_p) {
 		int has_head = 0;
 		for (i = 0; !has_head && i < ref_name_cnt; i++) {
 			/* We are only interested in adding the branch
 			 * HEAD points at.
 			 */
-			if (rev_is_head(head_path,
-					head_path_len,
+			if (rev_is_head(head,
+					head_len,
 					ref_name[i],
 					head_sha1, NULL))
 				has_head++;
 		}
 		if (!has_head) {
-			int pfxlen = strlen(git_path("refs/heads/"));
-			append_one_rev(head_path + pfxlen);
+			int pfxlen = strlen("refs/heads/");
+			append_one_rev(head + pfxlen);
 		}
 	}
 
@@ -713,8 +711,8 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 	if (1 < num_rev || extra < 0) {
 		for (i = 0; i < num_rev; i++) {
 			int j;
-			int is_head = rev_is_head(head_path,
-						  head_path_len,
+			int is_head = rev_is_head(head,
+						  head_len,
 						  ref_name[i],
 						  head_sha1,
 						  rev[i]->object.sha1);

builtin-show-ref.c

+#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[=<length>]] [--abbrev[=<length>]] [--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, abbrev = 0;
+static const char **pattern;
+
+static int show_ref(const char *refname, const unsigned char *sha1, int flag, void *cbdata)
+{
+	struct object *obj;
+	const char *hex;
+
+	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;
+
+	hex = find_unique_abbrev(sha1, abbrev);
+	if (hash_only)
+		printf("%s\n", hex);
+	else
+		printf("%s %s\n", hex, refname);
+	if (deref_tags && obj->type == OBJ_TAG) {
+		obj = deref_tag(obj, refname, 0);
+		hex = find_unique_abbrev(obj->sha1, abbrev);
+		printf("%s %s^{}\n", hex, 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 (!strncmp(arg, "--hash=", 7) ||
+		    (!strncmp(arg, "--abbrev", 8) &&
+		     (arg[8] == '=' || arg[8] == '\0'))) {
+			if (arg[3] != 'h' && !arg[8])
+				/* --abbrev only */
+				abbrev = DEFAULT_ABBREV;
+			else {
+				/* --hash= or --abbrev= */
+				char *end;
+				if (arg[3] == 'h') {
+					hash_only = 1;
+					arg += 7;
+				}
+				else
+					arg += 9;
+				abbrev = strtoul(arg, &end, 10);
+				if (*end || abbrev > 40)
+					usage(show_ref_usage);
+				if (abbrev < MINIMUM_ABBREV)
+					abbrev = MINIMUM_ABBREV;
+			}
+			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;
+}

builtin-symbolic-ref.c

 #include "builtin.h"
 #include "cache.h"
+#include "refs.h"
 
 static const char git_symbolic_ref_usage[] =
 "git-symbolic-ref name [ref]";
@@ -7,15 +8,14 @@ static const char git_symbolic_ref_usage[] =
 static void check_symref(const char *HEAD)
 {
 	unsigned char sha1[20];
-	const char *git_HEAD = xstrdup(git_path("%s", HEAD));
-	const char *git_refs_heads_master = resolve_ref(git_HEAD, sha1, 0);
-	if (git_refs_heads_master) {
-		/* we want to strip the .git/ part */
-		int pfxlen = strlen(git_HEAD) - strlen(HEAD);
-		puts(git_refs_heads_master + pfxlen);
-	}
-	else
+	int flag;
+	const char *refs_heads_master = resolve_ref(HEAD, sha1, 0, &flag);
+
+	if (!refs_heads_master)
 		die("No such ref: %s", HEAD);
+	else if (!(flag & REF_ISSYMREF))
+		die("ref %s is not a symbolic ref", HEAD);
+	puts(refs_heads_master);
 }
 
 int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
@@ -26,7 +26,7 @@ int cmd_symbolic_ref(int argc, const char **argv, const char *prefix)
 		check_symref(argv[1]);
 		break;
 	case 3:
-		create_symref(xstrdup(git_path("%s", argv[1])), argv[2]);
+		create_symref(argv[1], argv[2]);
 		break;
 	default:
 		usage(git_symbolic_ref_usage);

builtin-update-index.c

@@ -406,9 +406,9 @@ static int unresolve_one(const char *path)
 
 static void read_head_pointers(void)
 {
-	if (read_ref(git_path("HEAD"), head_sha1))
+	if (read_ref("HEAD", head_sha1))
 		die("No HEAD -- no initial commit yet?\n");
-	if (read_ref(git_path("MERGE_HEAD"), merge_head_sha1)) {
+	if (read_ref("MERGE_HEAD", merge_head_sha1)) {
 		fprintf(stderr, "Not in the middle of a merge.\n");
 		exit(0);
 	}
@@ -445,7 +445,7 @@ static int do_reupdate(int ac, const char **av,
 	int has_head = 1;
 	const char **pathspec = get_pathspec(prefix, av + 1);
 
-	if (read_ref(git_path("HEAD"), head_sha1))
+	if (read_ref("HEAD", head_sha1))
 		/* If there is no HEAD, that means it is an initial
 		 * commit.  Update everything in the index.
 		 */

builtin-update-ref.c

@@ -3,15 +3,16 @@
 #include "builtin.h"
 
 static const char git_update_ref_usage[] =
-"git-update-ref <refname> <value> [<oldval>] [-m <reason>]";
+"git-update-ref [-m <reason>] (-d <refname> <value> | <refname> <value> [<oldval>])";
 
 int cmd_update_ref(int argc, const char **argv, const char *prefix)
 {
 	const char *refname=NULL, *value=NULL, *oldval=NULL, *msg=NULL;
 	struct ref_lock *lock;
 	unsigned char sha1[20], oldsha1[20];
-	int i;
+	int i, delete;
 
+	delete = 0;
 	setup_ident();
 	git_config(git_default_config);
 
@@ -26,6 +27,10 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 				die("Refusing to perform update with \\n in message.");
 			continue;
 		}
+		if (!strcmp("-d", argv[i])) {
+			delete = 1;
+			continue;
+		}
 		if (!refname) {
 			refname = argv[i];
 			continue;
@@ -44,11 +49,18 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 
 	if (get_sha1(value, sha1))
 		die("%s: not a valid SHA1", value);
+
+	if (delete) {
+		if (oldval)
+			usage(git_update_ref_usage);
+		return delete_ref(refname, sha1);
+	}
+
 	hashclr(oldsha1);
-	if (oldval && get_sha1(oldval, oldsha1))
+	if (oldval && *oldval && get_sha1(oldval, oldsha1))
 		die("%s: not a valid old SHA1", oldval);
 
-	lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL, 0);
+	lock = lock_any_ref_for_update(refname, oldval ? oldsha1 : NULL);
 	if (!lock)
 		return 1;
 	if (write_ref_sha1(lock, sha1, msg) < 0)

builtin.h

@@ -17,6 +17,7 @@ extern int cmd_add(int argc, const char **argv, const char *prefix);
 extern int cmd_annotate(int argc, const char **argv, const char *prefix);
 extern int cmd_apply(int argc, const char **argv, const char *prefix);
 extern int cmd_archive(int argc, const char **argv, const char *prefix);
+extern int cmd_branch(int argc, const char **argv, const char *prefix);
 extern int cmd_cat_file(int argc, const char **argv, const char *prefix);
 extern int cmd_checkout_index(int argc, const char **argv, const char *prefix);
 extern int cmd_check_ref_format(int argc, const char **argv, const char *prefix);
@@ -65,5 +66,7 @@ extern int cmd_version(int argc, const char **argv, const char *prefix);
 extern int cmd_whatchanged(int argc, const char **argv, const char *prefix);
 extern int cmd_write_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_verify_pack(int argc, const char **argv, const char *prefix);
+extern int cmd_show_ref(int argc, const char **argv, const char *prefix);
+extern int cmd_pack_refs(int argc, const char **argv, const char *prefix);
 
 #endif

cache.h

@@ -179,6 +179,7 @@ struct lock_file {
 extern int hold_lock_file_for_update(struct lock_file *, const char *path, int);
 extern int commit_lock_file(struct lock_file *);
 extern void rollback_lock_file(struct lock_file *);
+extern int delete_ref(const char *, unsigned char *sha1);
 
 /* Environment bits from configuration mechanism */
 extern int use_legacy_headers;
@@ -288,9 +289,9 @@ extern int get_sha1(const char *str, unsigned char *sha1);
 extern int get_sha1_hex(const char *hex, unsigned char *sha1);
 extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
 extern int read_ref(const char *filename, unsigned char *sha1);
-extern const char *resolve_ref(const char *path, unsigned char *sha1, int);
-extern int create_symref(const char *git_HEAD, const char *refs_heads_master);
-extern int validate_symref(const char *git_HEAD);
+extern const char *resolve_ref(const char *path, unsigned char *sha1, int, int *);
+extern int create_symref(const char *ref, const char *refs_heads_master);
+extern int validate_symref(const char *ref);
 
 extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
 extern int cache_name_compare(const char *name1, int len1, const char *name2, int len2);

describe.c

@@ -53,7 +53,7 @@ static void add_to_known_names(const char *path,
 	names = ++idx;
 }
 
-static int get_name(const char *path, const unsigned char *sha1)
+static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 	struct object *object;
@@ -113,7 +113,7 @@ static void describe(const char *arg, int last_one)
 
 	if (!initialized) {
 		initialized = 1;
-		for_each_ref(get_name);
+		for_each_ref(get_name, NULL);
 		qsort(name_array, names, sizeof(*name_array), compare_names);
 	}
 

fetch-pack.c

@@ -42,7 +42,7 @@ static void rev_list_push(struct commit *commit, int mark)
 	}
 }
 
-static int rev_list_insert_ref(const char *path, const unsigned char *sha1)
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *o = deref_tag(parse_object(sha1), path, 0);
 
@@ -143,7 +143,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 	unsigned in_vain = 0;
 	int got_continue = 0;
 
-	for_each_ref(rev_list_insert_ref);
+	for_each_ref(rev_list_insert_ref, NULL);
 
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
@@ -254,7 +254,7 @@ static int find_common(int fd[2], unsigned char *result_sha1,
 
 static struct commit_list *complete;
 
-static int mark_complete(const char *path, const unsigned char *sha1)
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *o = parse_object(sha1);
 
@@ -366,7 +366,7 @@ static int everything_local(struct ref **refs, int nr_match, char **match)
 		}
 	}
 
-	for_each_ref(mark_complete);
+	for_each_ref(mark_complete, NULL);
 	if (cutoff)
 		mark_recent_complete_commits(cutoff);
 

fetch.c

@@ -201,7 +201,7 @@ static int interpret_target(char *target, unsigned char *sha1)
 	return -1;
 }
 
-static int mark_complete(const char *path, const unsigned char *sha1)
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 	if (commit) {
@@ -266,7 +266,7 @@ int pull(int targets, char **target, const char **write_ref,
 		if (!write_ref || !write_ref[i])
 			continue;
 
-		lock[i] = lock_ref_sha1(write_ref[i], NULL, 0);
+		lock[i] = lock_ref_sha1(write_ref[i], NULL);
 		if (!lock[i]) {
 			error("Can't lock ref %s", write_ref[i]);
 			goto unlock_and_fail;
@@ -274,7 +274,7 @@ int pull(int targets, char **target, const char **write_ref,
 	}
 
 	if (!get_recover)
-		for_each_ref(mark_complete);
+		for_each_ref(mark_complete, NULL);
 
 	for (i = 0; i < targets; i++) {
 		if (interpret_target(target[i], &sha1[20 * i])) {

fsck-objects.c

@@ -402,7 +402,7 @@ static void fsck_dir(int i, char *path)
 
 static int default_refs;
 
-static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
+static int fsck_handle_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *obj;
 
@@ -424,7 +424,7 @@ static int fsck_handle_ref(const char *refname, const unsigned char *sha1)
 
 static void get_default_heads(void)
 {
-	for_each_ref(fsck_handle_ref);
+	for_each_ref(fsck_handle_ref, NULL);
 
 	/*
 	 * Not having any default heads isn't really fatal, but
@@ -458,15 +458,14 @@ static void fsck_object_dir(const char *path)
 static int fsck_head_link(void)
 {
 	unsigned char sha1[20];
-	const char *git_HEAD = xstrdup(git_path("HEAD"));
-	const char *git_refs_heads_master = resolve_ref(git_HEAD, sha1, 1);
-	int pfxlen = strlen(git_HEAD) - 4; /* strip .../.git/ part */
+	int flag;
+	const char *head_points_at = resolve_ref("HEAD", sha1, 1, &flag);
 
-	if (!git_refs_heads_master)
+	if (!head_points_at || !(flag & REF_ISSYMREF))
 		return error("HEAD is not a symbolic ref");
-	if (strncmp(git_refs_heads_master + pfxlen, "refs/heads/", 11))
+	if (strncmp(head_points_at, "refs/heads/", 11))
 		return error("HEAD points to something strange (%s)",
-			     git_refs_heads_master + pfxlen);
+			     head_points_at);
 	if (is_null_sha1(sha1))
 		return error("HEAD: not a valid git pointer");
 	return 0;

git-branch.sh

-#!/bin/sh
-
-USAGE='[-l] [-f] <branchname> [<start-point>] | (-d | -D) <branchname> | [-r]'
-LONG_USAGE='If no arguments, show available branches and mark current branch with a star.
-If one argument, create a new branch <branchname> based off of current HEAD.
-If two arguments, create a new branch <branchname> based off of <start-point>.'
-
-SUBDIRECTORY_OK='Yes'
-. git-sh-setup
-
-headref=$(git-symbolic-ref HEAD | sed -e 's|^refs/heads/||')
-
-delete_branch () {
-    option="$1"
-    shift
-    for branch_name
-    do
-	case ",$headref," in
-	",$branch_name,")
-	    die "Cannot delete the branch you are on." ;;
-	,,)
-	    die "What branch are you on anyway?" ;;
-	esac
-	branch=$(cat "$GIT_DIR/refs/heads/$branch_name") &&
-	    branch=$(git-rev-parse --verify "$branch^0") ||
-		die "Seriously, what branch are you talking about?"
-	case "$option" in
-	-D)
-	    ;;
-	*)
-	    mbs=$(git-merge-base -a "$branch" HEAD | tr '\012' ' ')
-	    case " $mbs " in
-	    *' '$branch' '*)
-		# the merge base of branch and HEAD contains branch --
-		# which means that the HEAD contains everything in both.
-		;;
-	    *)
-		echo >&2 "The branch '$branch_name' is not a strict subset of your current HEAD.
-If you are sure you want to delete it, run 'git branch -D $branch_name'."
-		exit 1
-		;;
-	    esac
-	    ;;
-	esac
-	rm -f "$GIT_DIR/logs/refs/heads/$branch_name"
-	rm -f "$GIT_DIR/refs/heads/$branch_name"
-	echo "Deleted branch $branch_name."
-    done
-    exit 0
-}
-
-ls_remote_branches () {
-    git-rev-parse --symbolic --all |
-    sed -ne 's|^refs/\(remotes/\)|\1|p' |
-    sort
-}
-
-force=
-create_log=
-while case "$#,$1" in 0,*) break ;; *,-*) ;; *) break ;; esac
-do
-	case "$1" in
-	-d | -D)
-		delete_branch "$@"
-		exit
-		;;
-	-r)
-		ls_remote_branches
-		exit
-		;;
-	-f)
-		force="$1"
-		;;
-	-l)
-		create_log="yes"
-		;;
-	--)
-		shift
-		break
-		;;
-	-*)
-		usage
-		;;
-	esac
-	shift
-done
-
-case "$#" in
-0)
-	git-rev-parse --symbolic --branches |
-	sort |
-	while read ref
-	do
-		if test "$headref" = "$ref"
-		then
-			pfx='*'
-		else
-			pfx=' '
-		fi
-		echo "$pfx $ref"
-	done
-	exit 0 ;;
-1)
-	head=HEAD ;;
-2)
-	head="$2^0" ;;
-esac
-branchname="$1"
-
-rev=$(git-rev-parse --verify "$head") || exit
-
-git-check-ref-format "heads/$branchname" ||
-	die "we do not like '$branchname' as a branch name."
-
-if [ -d "$GIT_DIR/refs/heads/$branchname" ]
-then
-	for refdir in `cd "$GIT_DIR" && \
-		find "refs/heads/$branchname" -type d | sort -r`
-	do
-		rmdir "$GIT_DIR/$refdir" || \
-		    die "Could not delete '$refdir', there may still be a ref there."
-	done
-fi
-
-if [ -e "$GIT_DIR/refs/heads/$branchname" ]
-then
-	if test '' = "$force"
-	then
-		die "$branchname already exists."
-	elif test "$branchname" = "$headref"
-	then
-		die "cannot force-update the current branch."
-	fi
-fi
-if test "$create_log" = 'yes'
-then
-	mkdir -p $(dirname "$GIT_DIR/logs/refs/heads/$branchname")
-	touch "$GIT_DIR/logs/refs/heads/$branchname"
-fi
-git update-ref -m "branch: Created from $head" "refs/heads/$branchname" $rev

git-checkout.sh

@@ -22,7 +22,7 @@ while [ "$#" != "0" ]; do
 		shift
 		[ -z "$newbranch" ] &&
 			die "git checkout: -b needs a branch name"
-		[ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
+		git-show-ref --verify --quiet -- "refs/heads/$newbranch" &&
 			die "git checkout: branch $newbranch already exists"
 		git-check-ref-format "heads/$newbranch" ||
 			die "git checkout: we do not like '$newbranch' as a branch name."
@@ -51,7 +51,8 @@ while [ "$#" != "0" ]; do
 			fi
 			new="$rev"
 			new_name="$arg^0"
-			if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+			if git-show-ref --verify --quiet -- "refs/heads/$arg"
+			then
 				branch="$arg"
 			fi
 		elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)

git-commit.sh

@@ -441,7 +441,7 @@ then
 elif test "$use_commit" != ""
 then
 	git-cat-file commit "$use_commit" | sed -e '1,/^$/d'
-elif test -f "$GIT_DIR/MERGE_HEAD" && test -f "$GIT_DIR/MERGE_MSG"
+elif test -f "$GIT_DIR/MERGE_MSG"
 then
 	cat "$GIT_DIR/MERGE_MSG"
 elif test -f "$GIT_DIR/SQUASH_MSG"
@@ -522,15 +522,15 @@ then
 		PARENTS=$(git-cat-file commit HEAD |
 			sed -n -e '/^$/q' -e 's/^parent /-p /p')
 	fi
-	current=$(git-rev-parse --verify HEAD)
+	current="$(git-rev-parse --verify HEAD)"
 else
 	if [ -z "$(git-ls-files)" ]; then
 		echo >&2 Nothing to commit
 		exit 1
 	fi
 	PARENTS=""
-	current=
 	rloga='commit (initial)'
+	current=''
 fi
 
 if test -z "$no_edit"
@@ -606,8 +606,8 @@ then
 	fi &&
 	commit=$(cat "$GIT_DIR"/COMMIT_MSG | git-commit-tree $tree $PARENTS) &&
 	rlogm=$(sed -e 1q "$GIT_DIR"/COMMIT_MSG) &&
-	git-update-ref -m "$rloga: $rlogm" HEAD $commit $current &&
-	rm -f -- "$GIT_DIR/MERGE_HEAD" &&
+	git-update-ref -m "$rloga: $rlogm" HEAD $commit "$current" &&
+	rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" &&
 	if test -f "$NEXT_INDEX"
 	then
 		mv "$NEXT_INDEX" "$THIS_INDEX"

git-fetch.sh

@@ -427,7 +427,7 @@ case "$no_tags$tags" in
 		sed -ne 's|^\([0-9a-f]*\)[ 	]\(refs/tags/.*\)^{}$|\1 \2|p' |
 		while read sha1 name
 		do
-			test -f "$GIT_DIR/$name" && continue
+			git-show-ref --verify --quiet -- $name && continue
 			git-check-ref-format "$name" || {
 				echo >&2 "warning: tag ${name} ignored"
 				continue

git-revert.sh

@@ -145,9 +145,18 @@ git-read-tree -m -u --aggressive $base $head $next &&
 result=$(git-write-tree 2>/dev/null) || {
     echo >&2 "Simple $me fails; trying Automatic $me."
     git-merge-index -o git-merge-one-file -a || {
+	    mv -f .msg "$GIT_DIR/MERGE_MSG"
+	    {
+		echo '
+Conflicts:
+'
+		git ls-files --unmerged |
+		sed -e 's/^[^	]*	/	/' |
+		uniq
+	    } >>"$GIT_DIR/MERGE_MSG"
 	    echo >&2 "Automatic $me failed.  After resolving the conflicts,"
 	    echo >&2 "mark the corrected paths with 'git-update-index <paths>'"
-	    echo >&2 "and commit with 'git commit -F .msg'"
+	    echo >&2 "and commit the result."
 	    case "$me" in
 	    cherry-pick)
 		echo >&2 "You may choose to use the following when making"

git-tag.sh

@@ -47,8 +47,10 @@ do
     -d)
     	shift
 	tag_name="$1"
-	rm "$GIT_DIR/refs/tags/$tag_name" && \
-	        echo "Deleted tag $tag_name."
+	tag=$(git-show-ref --verify --hash -- "refs/tags/$tag_name") ||
+		die "Seriously, what tag are you talking about?"
+	git-update-ref -m 'tag: delete' -d "refs/tags/$tag_name" "$tag" &&
+		echo "Deleted tag $tag_name."
 	exit $?
 	;;
     -*)
@@ -63,8 +65,11 @@ done
 
 name="$1"
 [ "$name" ] || usage
-if [ -e "$GIT_DIR/refs/tags/$name" -a -z "$force" ]; then
-    die "tag '$name' already exists"
+prev=0000000000000000000000000000000000000000
+if git-show-ref --verify --quiet -- "refs/tags/$name"
+then
+    test -n "$force" || die "tag '$name' already exists"
+    prev=`git rev-parse "refs/tags/$name"`
 fi
 shift
 git-check-ref-format "tags/$name" ||
@@ -107,6 +112,5 @@ if [ "$annotate" ]; then
     object=$(git-mktag < "$GIT_DIR"/TAG_TMP)
 fi
 
-leading=`expr "refs/tags/$name" : '\(.*\)/'` &&
-mkdir -p "$GIT_DIR/$leading" &&
-echo $object > "$GIT_DIR/refs/tags/$name"
+git update-ref "refs/tags/$name" "$object" "$prev"
+

git.c

@@ -222,6 +222,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "annotate", cmd_annotate, },
 		{ "apply", cmd_apply },
 		{ "archive", cmd_archive },
+		{ "branch", cmd_branch },
 		{ "cat-file", cmd_cat_file, RUN_SETUP },
 		{ "checkout-index", cmd_checkout_index, RUN_SETUP },
 		{ "check-ref-format", cmd_check_ref_format },
@@ -269,6 +270,8 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
 		{ "write-tree", cmd_write_tree, RUN_SETUP },
 		{ "verify-pack", cmd_verify_pack },
+		{ "show-ref", cmd_show_ref, RUN_SETUP },
+		{ "pack-refs", cmd_pack_refs, RUN_SETUP },
 	};
 	int i;
 

http-push.c

@@ -1864,7 +1864,7 @@ static int update_remote(unsigned char *sha1, struct remote_lock *lock)
 static struct ref *local_refs, **local_tail;
 static struct ref *remote_refs, **remote_tail;
 
-static int one_local_ref(const char *refname, const unsigned char *sha1)
+static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct ref *ref;
 	int len = strlen(refname) + 1;
@@ -1913,7 +1913,7 @@ static void one_remote_ref(char *refname)
 static void get_local_heads(void)
 {
 	local_tail = &local_refs;
-	for_each_ref(one_local_ref);
+	for_each_ref(one_local_ref, NULL);
 }
 
 static void get_dav_remote_heads(void)

receive-pack.c

@@ -28,7 +28,7 @@ static int receive_pack_config(const char *var, const char *value)
 	return 0;
 }
 
-static int show_ref(const char *path, const unsigned char *sha1)
+static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	if (capabilities_sent)
 		packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
@@ -41,9 +41,9 @@ static int show_ref(const char *path, const unsigned char *sha1)
 
 static void write_head_info(void)
 {
-	for_each_ref(show_ref);
+	for_each_ref(show_ref, NULL);
 	if (!capabilities_sent)
-		show_ref("capabilities^{}", null_sha1);
+		show_ref("capabilities^{}", null_sha1, 0, NULL);
 
 }
 
@@ -57,34 +57,6 @@ struct command {
 
 static struct command *commands;
 
-static int is_all_zeroes(const char *hex)
-{
-	int i;
-	for (i = 0; i < 40; i++)
-		if (*hex++ != '0')
-			return 0;
-	return 1;
-}
-
-static int verify_old_ref(const char *name, char *hex_contents)
-{
-	int fd, ret;
-	char buffer[60];
-
-	if (is_all_zeroes(hex_contents))
-		return 0;
-	fd = open(name, O_RDONLY);
-	if (fd < 0)
-		return -1;
-	ret = read(fd, buffer, 40);
-	close(fd);
-	if (ret != 40)
-		return -1;
-	if (memcmp(buffer, hex_contents, 40))
-		return -1;
-	return 0;
-}
-
 static char update_hook[] = "hooks/update";
 
 static int run_update_hook(const char *refname,
@@ -121,8 +93,8 @@ static int update(struct command *cmd)
 	const char *name = cmd->ref_name;
 	unsigned char *old_sha1 = cmd->old_sha1;
 	unsigned char *new_sha1 = cmd->new_sha1;
-	char new_hex[60], *old_hex, *lock_name;
-	int newfd, namelen, written;
+	char new_hex[41], old_hex[41];
+	struct ref_lock *lock;
 
 	cmd->error_string = NULL;
 	if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
@@ -131,13 +103,8 @@ static int update(struct command *cmd)
 			     name);
 	}
 
-	namelen = strlen(name);
-	lock_name = xmalloc(namelen + 10);
-	memcpy(lock_name, name, namelen);
-	memcpy(lock_name + namelen, ".lock", 6);
-
 	strcpy(new_hex, sha1_to_hex(new_sha1));
-	old_hex = sha1_to_hex(old_sha1);
+	strcpy(old_hex, sha1_to_hex(old_sha1));
 	if (!has_sha1_file(new_sha1)) {
 		cmd->error_string = "bad pack";
 		return error("unpack should have generated %s, "
@@ -158,47 +125,20 @@ static int update(struct command *cmd)
 			return error("denying non-fast forward;"
 				     " you should pull first");
 	}
-	safe_create_leading_directories(lock_name);
-
-	newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
-	if (newfd < 0) {
-		cmd->error_string = "can't lock";
-		return error("unable to create %s (%s)",
-			     lock_name, strerror(errno));
-	}
-
-	/* Write the ref with an ending '\n' */
-	new_hex[40] = '\n';
-	new_hex[41] = 0;
-	written = write(newfd, new_hex, 41);
-	/* Remove the '\n' again */
-	new_hex[40] = 0;
-
-	close(newfd);
-	if (written != 41) {
-		unlink(lock_name);
-		cmd->error_string = "can't write";
-		return error("unable to write %s", lock_name);
-	}
-	if (verify_old_ref(name, old_hex) < 0) {
-		unlink(lock_name);
-		cmd->error_string = "raced";
-		return error("%s changed during push", name);
-	}
 	if (run_update_hook(name, old_hex, new_hex)) {
-		unlink(lock_name);
 		cmd->error_string = "hook declined";
 		return error("hook declined to update %s", name);
 	}
-	else if (rename(lock_name, name) < 0) {
-		unlink(lock_name);
-		cmd->error_string = "can't rename";
-		return error("unable to replace %s", name);
-	}
-	else {
-		fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
-		return 0;
+
+	lock = lock_any_ref_for_update(name, old_sha1);
+	if (!lock) {
+		cmd->error_string = "failed to lock";
+		return error("failed to lock %s", name);
 	}
+	write_ref_sha1(lock, new_sha1, "push");
+
+	fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
+	return 0;
 }
 
 static char update_post_hook[] = "hooks/post-update";
@@ -349,9 +289,10 @@ int main(int argc, char **argv)
 	if (!dir)
 		usage(receive_pack_usage);
 
-	if(!enter_repo(dir, 0))
+	if (!enter_repo(dir, 0))
 		die("'%s': unable to chdir or not a git archive", dir);
 
+	setup_ident();
 	git_config(receive_pack_config);
 
 	write_head_info();

refs.h

@@ -2,7 +2,7 @@
 #define REFS_H
 
 struct ref_lock {
-	char *ref_file;
+	char *ref_name;
 	char *log_file;
 	struct lock_file *lk;
 	unsigned char old_sha1[20];
@@ -14,20 +14,23 @@ struct ref_lock {
  * Calls the specified function for each ref file until it returns nonzero,
  * and returns the value
  */
-extern int head_ref(int (*fn)(const char *path, const unsigned char *sha1));
-extern int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1));
-extern int for_each_tag_ref(int (*fn)(const char *path, const unsigned char *sha1));
-extern int for_each_branch_ref(int (*fn)(const char *path, const unsigned char *sha1));
-extern int for_each_remote_ref(int (*fn)(const char *path, const unsigned char *sha1));
+#define REF_ISSYMREF 01
+#define REF_ISPACKED 02
+typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data);
+extern int head_ref(each_ref_fn, void *);
+extern int for_each_ref(each_ref_fn, void *);
+extern int for_each_tag_ref(each_ref_fn, void *);
+extern int for_each_branch_ref(each_ref_fn, void *);
+extern int for_each_remote_ref(each_ref_fn, void *);
 
 /** Reads the refs file specified into sha1 **/
 extern int get_ref_sha1(const char *ref, unsigned char *sha1);
 
 /** Locks a "refs/" ref returning the lock on success and NULL on failure. **/
-extern struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1, int mustexist);
+extern struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1);
 
 /** Locks any ref (for 'HEAD' type refs). */
-extern struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int mustexist);
+extern struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1);
 
 /** Release any lock taken but not written. **/
 extern void unlock_ref(struct ref_lock *lock);
@@ -36,7 +39,7 @@ extern void unlock_ref(struct ref_lock *lock);
 extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg);
 
 /** Reads log for the value of ref during at_time. **/
-extern int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1);
+extern int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1);
 
 /** Returns 0 if target has the right format for a ref. **/
 extern int check_ref_format(const char *target);

revision.c

@@ -465,7 +465,7 @@ static void limit_list(struct rev_info *revs)
 static int all_flags;
 static struct rev_info *all_revs;
 
-static int handle_one_ref(const char *path, const unsigned char *sha1)
+static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *object = get_reference(all_revs, path, sha1, all_flags);
 	add_pending_object(all_revs, object, "");
@@ -476,7 +476,7 @@ static void handle_all(struct rev_info *revs, unsigned flags)
 {
 	all_revs = revs;
 	all_flags = flags;
-	for_each_ref(handle_one_ref);
+	for_each_ref(handle_one_ref, NULL);
 }
 
 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)

send-pack.c

@@ -215,7 +215,7 @@ static int ref_newer(const unsigned char *new_sha1,
 static struct ref *local_refs, **local_tail;
 static struct ref *remote_refs, **remote_tail;
 
-static int one_local_ref(const char *refname, const unsigned char *sha1)
+static int one_local_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct ref *ref;
 	int len = strlen(refname) + 1;
@@ -230,7 +230,7 @@ static int one_local_ref(const char *refname, const unsigned char *sha1)
 static void get_local_heads(void)
 {
 	local_tail = &local_refs;
-	for_each_ref(one_local_ref);
+	for_each_ref(one_local_ref, NULL);
 }
 
 static int receive_status(int in)

server-info.c

@@ -7,7 +7,7 @@
 /* refs */
 static FILE *info_ref_fp;
 
-static int add_info_ref(const char *path, const unsigned char *sha1)
+static int add_info_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 {
 	struct object *o = parse_object(sha1);
 
@@ -34,7 +34,7 @@ static int update_info_refs(int force)
 	info_ref_fp = fopen(path1, "w");
 	if (!info_ref_fp)
 		return error("unable to update %s", path0);
-	for_each_ref(add_info_ref);
+	for_each_ref(add_info_ref, NULL);
 	fclose(info_ref_fp);
 	rename(path1, path0);
 	free(path0);

sha1_name.c

@@ -247,26 +247,25 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 		NULL
 	};
 	static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
-	const char **p, *pathname;
-	char *real_path = NULL;
-	int refs_found = 0, am;
-	unsigned long at_time = (unsigned long)-1;
+	const char **p, *ref;
+	char *real_ref = NULL;
+	int refs_found = 0;
+	int at, reflog_len;
 	unsigned char *this_result;
 	unsigned char sha1_from_ref[20];
 
 	if (len == 40 && !get_sha1_hex(str, sha1))
 		return 0;
 
-	/* At a given period of time? "@{2 hours ago}" */
-	for (am = 1; am < len - 1; am++) {
-		if (str[am] == '@' && str[am+1] == '{' && str[len-1] == '}') {
-			int date_len = len - am - 3;
-			char *date_spec = xmalloc(date_len + 1);
-			strlcpy(date_spec, str + am + 2, date_len + 1);
-			at_time = approxidate(date_spec);
-			free(date_spec);
-			len = am;
-			break;
+	/* basic@{time or number} format to query ref-log */
+	reflog_len = at = 0;
+	if (str[len-1] == '}') {
+		for (at = 1; at < len - 1; at++) {
+			if (str[at] == '@' && str[at+1] == '{') {
+				reflog_len = (len-1) - (at+2);
+				len = at;
+				break;
+			}
 		}
 	}
 
@@ -276,10 +275,10 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 
 	for (p = fmt; *p; p++) {
 		this_result = refs_found ? sha1_from_ref : sha1;
-		pathname = resolve_ref(git_path(*p, len, str), this_result, 1);
-		if (pathname) {
+		ref = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
+		if (ref) {
 			if (!refs_found++)
-				real_path = xstrdup(pathname);
+				real_ref = xstrdup(ref);
 			if (!warn_ambiguous_refs)
 				break;
 		}
@@ -291,14 +290,25 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 	if (warn_ambiguous_refs && refs_found > 1)
 		fprintf(stderr, warning, len, str);
 
-	if (at_time != (unsigned long)-1) {
-		read_ref_at(
-			real_path + strlen(git_path(".")) - 1,
-			at_time,
-			sha1);
+	if (reflog_len) {
+		/* Is it asking for N-th entry, or approxidate? */
+		int nth, i;
+		unsigned long at_time;
+		for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
+			char ch = str[at+2+i];
+			if ('0' <= ch && ch <= '9')
+				nth = nth * 10 + ch - '0';
+			else
+				nth = -1;
+		}
+		if (0 <= nth)
+			at_time = 0;
+		else
+			at_time = approxidate(str + at + 2);
+		read_ref_at(real_ref, at_time, nth, sha1);
 	}
 
-	free(real_path);
+	free(real_ref);
 	return 0;
 }
 

t/t1400-update-ref.sh

@@ -30,11 +30,8 @@ rm -f .git/$m
 test_expect_success \
 	"fail to create $n" \
 	"touch .git/$n_dir
-	 git-update-ref $n $A >out 2>err
-	 test "'$? = 1 &&
-	 test "" = "$(cat out)" &&
-	 grep "error: unable to resolve reference" err &&
-	 grep '"$n err"
+	 git-update-ref $n $A >out 2>err"'
+	 test $? != 0'
 rm -f .git/$n_dir out err
 
 test_expect_success \

t/t3200-branch.sh

@@ -17,13 +17,10 @@ test_expect_success \
      git-commit -m "Initial commit." &&
      HEAD=$(git-rev-parse --verify HEAD)'
 
-test_expect_success \
-    'git branch --help should return success now.' \
-    'git-branch --help'
-
 test_expect_failure \
     'git branch --help should not have created a bogus branch' \
-    'test -f .git/refs/heads/--help'
+    'git-branch --help </dev/null >/dev/null 2>/dev/null || :
+     test -f .git/refs/heads/--help'
 
 test_expect_success \
     'git branch abc should create a branch' \
@@ -34,7 +31,7 @@ test_expect_success \
     'git-branch a/b/c && test -f .git/refs/heads/a/b/c'
 
 cat >expect <<EOF
-0000000000000000000000000000000000000000 $HEAD $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	branch: Created from HEAD
+0000000000000000000000000000000000000000 $HEAD $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1117150200 +0000	branch: Created from master
 EOF
 test_expect_success \
     'git branch -l d/e/f should create a branch and a log' \

t/t3210-pack-refs.sh

+#!/bin/sh
+#
+# Copyright (c) 2005 Amos Waterland
+# Copyright (c) 2006 Christian Couder
+#
+
+test_description='git pack-refs should not change the branch semantic
+
+This test runs git pack-refs and git show-ref and checks that the branch
+semantic is still the same.
+'
+. ./test-lib.sh
+
+echo '[core] logallrefupdates = true' >>.git/config
+
+test_expect_success \
+    'prepare a trivial repository' \
+    'echo Hello > A &&
+     git-update-index --add A &&
+     git-commit -m "Initial commit." &&
+     HEAD=$(git-rev-parse --verify HEAD)'
+
+SHA1=
+
+test_expect_success \
+    'see if git show-ref works as expected' \
+    'git-branch a &&
+     SHA1=`cat .git/refs/heads/a` &&
+     echo "$SHA1 refs/heads/a" >expect &&
+     git-show-ref a >result &&
+     diff expect result'
+
+test_expect_success \
+    'see if a branch still exists when packed' \
+    'git-branch b &&
+     git-pack-refs --all &&
+     rm .git/refs/heads/b &&
+     echo "$SHA1 refs/heads/b" >expect &&
+     git-show-ref b >result &&
+     diff expect result'
+
+test_expect_failure \
+    'git branch c/d should barf if branch c exists' \
+    'git-branch c &&
+     git-pack-refs --all &&
+     rm .git/refs/heads/c &&
+     git-branch c/d'
+
+test_expect_success \
+    'see if a branch still exists after git pack-refs --prune' \
+    'git-branch e &&
+     git-pack-refs --all --prune &&
+     echo "$SHA1 refs/heads/e" >expect &&
+     git-show-ref e >result &&
+     diff expect result'
+
+test_expect_failure \
+    'see if git pack-refs --prune remove ref files' \
+    'git-branch f &&
+     git-pack-refs --all --prune &&
+     ls .git/refs/heads/f'
+
+test_expect_success \
+    'git branch g should work when git branch g/h has been deleted' \
+    'git-branch g/h &&
+     git-pack-refs --all --prune &&
+     git-branch -d g/h &&
+     git-branch g &&
+     git-pack-refs --all &&
+     git-branch -d g'
+
+test_expect_failure \
+    'git branch i/j/k should barf if branch i exists' \
+    'git-branch i &&
+     git-pack-refs --all --prune &&
+     git-branch i/j/k'
+
+test_expect_success \
+    'test git branch k after branch k/l/m and k/lm have been deleted' \
+    'git-branch k/l &&
+     git-branch k/lm &&
+     git-branch -d k/l &&
+     git-branch k/l/m &&
+     git-branch -d k/l/m &&
+     git-branch -d k/lm &&
+     git-branch k'
+
+test_expect_success \
+    'test git branch n after some branch deletion and pruning' \
+    'git-branch n/o &&
+     git-branch n/op &&
+     git-branch -d n/o &&
+     git-branch n/o/p &&
+     git-branch -d n/op &&
+     git-pack-refs --all --prune &&
+     git-branch -d n/o/p &&
+     git-branch n'
+
+test_done

upload-pack.c

@@ -420,7 +420,7 @@ static void receive_needs(void)
 	}
 }
 
-static int send_ref(const char *refname, const unsigned char *sha1)
+static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
 	static const char *capabilities = "multi_ack thin-pack side-band side-band-64k ofs-delta";
 	struct object *o = parse_object(sha1);
@@ -448,8 +448,8 @@ static int send_ref(const char *refname, const unsigned char *sha1)
 static void upload_pack(void)
 {
 	reset_timeout();
-	head_ref(send_ref);
-	for_each_ref(send_ref);
+	head_ref(send_ref, NULL);
+	for_each_ref(send_ref, NULL);
 	packet_flush(1);
 	receive_needs();
 	if (want_obj.nr) {

wt-status.c

@@ -41,10 +41,8 @@ void wt_status_prepare(struct wt_status *s)
 
 	s->is_initial = get_sha1("HEAD", sha1) ? 1 : 0;
 
-	head = resolve_ref(git_path("HEAD"), sha1, 0);
-	s->branch = head ?
-		    strdup(head + strlen(get_git_dir()) + 1) :
-		    NULL;
+	head = resolve_ref("HEAD", sha1, 0, NULL);
+	s->branch = head ? xstrdup(head) : NULL;
 
 	s->reference = "HEAD";
 	s->amend = 0;