[PATCH 00/33] Various cleanups around reference packing and peeling

@@ -109,7 +109,19 @@ struct ref_entry;
  * (ref_entry->flag & REF_DIR) is zero.
  */
 struct ref_value {
+	/*
+	 * The name of the object to which this reference resolves
+	 * (which may be a tag object).  If REF_ISBROKEN, this is
+	 * null.  If REF_ISSYMREF, then this is the name of the object
+	 * referred to by the last reference in the symlink chain.
+	 */
 	unsigned char sha1[20];
+
+	/*
+	 * If REF_KNOWS_PEELED, then this field holds the peeled value
+	 * of this reference, or null if the reference is known not to
+	 * be peelable.
+	 */
 	unsigned char peeled[20];
 };
 

@@ -1282,10 +1282,9 @@ int peel_ref(const char *refname, unsigned char *sha1)
 		return -1;
 
 	if ((flag & REF_ISPACKED)) {
-		struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
-		struct ref_entry *r = find_ref(dir, refname);
+		struct ref_entry *r = get_packed_ref(refname);
 
-		if (r != NULL && r->flag & REF_KNOWS_PEELED) {
+		if (r && (r->flag & REF_KNOWS_PEELED)) {
 			hashcpy(sha1, r->u.value.peeled);
 			return 0;
 		}

@@ -1272,32 +1272,48 @@ static int filter_refs(const char *refname, const unsigned char *sha1, int flags
 	return filter->fn(refname, sha1, flags, filter->cb_data);
 }
 
+enum peel_status {
+	/* object was peeled successfully: */
+	PEEL_PEELED = 0,
+
+	/*
+	 * object cannot be peeled because the named object (or an
+	 * object referred to by a tag in the peel chain), does not
+	 * exist.
+	 */
+	PEEL_INVALID = -1,
+
+	/* object cannot be peeled because it is not a tag: */
+	PEEL_NON_TAG = -2,
+};
+
 /*
  * Peel the named object; i.e., if the object is a tag, resolve the
- * tag recursively until a non-tag is found.  Store the result to sha1
- * and return 0 iff successful.  If the object is not a tag or is not
- * valid, return -1 and leave sha1 unchanged.
+ * tag recursively until a non-tag is found.  If successful, store the
+ * result to sha1 and return PEEL_PEELED.  If the object is not a tag
+ * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
+ * and leave sha1 unchanged.
  */
-static int peel_object(const unsigned char *name, unsigned char *sha1)
+static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
 {
 	struct object *o = lookup_unknown_object(name);
 
 	if (o->type == OBJ_NONE) {
 		int type = sha1_object_info(name, NULL);
 		if (type < 0)
-			return -1;
+			return PEEL_INVALID;
 		o->type = type;
 	}
 
 	if (o->type != OBJ_TAG)
-		return -1;
+		return PEEL_NON_TAG;
 
 	o = deref_tag_noverify(o);
 	if (!o)
-		return -1;
+		return PEEL_INVALID;
 
 	hashcpy(sha1, o->sha1);
-	return 0;
+	return PEEL_PEELED;
 }
 
 int peel_ref(const char *refname, unsigned char *sha1)

@@ -556,22 +556,34 @@ static int ref_resolves_to_object(struct ref_entry *entry)
  */
 static struct ref_entry *current_ref;
 
+typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
+
+struct ref_entry_cb {
+	const char *base;
+	int trim;
+	int flags;
+	each_ref_fn *fn;
+	void *cb_data;
+};
+
 /*
- * Handle one reference in a do_for_each_ref*()-style iteration.
+ * Handle one reference in a do_for_each_ref*()-style iteration,
+ * calling an each_ref_fn for each entry.
  */
-static int do_one_ref(const char *base, each_ref_fn fn, int trim,
-		      int flags, void *cb_data, struct ref_entry *entry)
+static int do_one_ref(struct ref_entry *entry, void *cb_data)
 {
+	struct ref_entry_cb *data = cb_data;
 	int retval;
-	if (prefixcmp(entry->name, base))
+	if (prefixcmp(entry->name, data->base))
 		return 0;
 
-	if (!((flags & DO_FOR_EACH_INCLUDE_BROKEN) ||
+	if (!((data->flags & DO_FOR_EACH_INCLUDE_BROKEN) ||
 	      ref_resolves_to_object(entry)))
 		return 0;
 
 	current_ref = entry;
-	retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
+	retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
+			  entry->flag, data->cb_data);
 	current_ref = NULL;
 	return retval;
 }

@@ -580,11 +592,11 @@ static int do_one_ref(const char *base, each_ref_fn fn, int trim,
  * Call fn for each reference in dir that has index in the range
  * offset <= index < dir->nr.  Recurse into subdirectories that are in
  * that index range, sorting them before iterating.  This function
- * does not sort dir itself; it should be sorted beforehand.
+ * does not sort dir itself; it should be sorted beforehand.  fn is
+ * called for all references, including broken ones.
  */
-static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
-				  const char *base,
-				  each_ref_fn fn, int trim, int flags, void *cb_data)
+static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
+				    each_ref_entry_fn fn, void *cb_data)
 {
 	int i;
 	assert(dir->sorted == dir->nr);

@@ -594,10 +606,9 @@ static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
 		if (entry->flag & REF_DIR) {
 			struct ref_dir *subdir = get_ref_dir(entry);
 			sort_ref_dir(subdir);
-			retval = do_for_each_ref_in_dir(subdir, 0,
-							base, fn, trim, flags, cb_data);
+			retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
 		} else {
-			retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
+			retval = fn(entry, cb_data);
 		}
 		if (retval)
 			return retval;

@@ -610,12 +621,12 @@ static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
  * by refname.  Recurse into subdirectories.  If a value entry appears
  * in both dir1 and dir2, then only process the version that is in
  * dir2.  The input dirs must already be sorted, but subdirs will be
- * sorted as needed.
+ * sorted as needed.  fn is called for all references, including
+ * broken ones.
  */
-static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
-				   struct ref_dir *dir2,
-				   const char *base, each_ref_fn fn, int trim,
-				   int flags, void *cb_data)
+static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
+				     struct ref_dir *dir2,
+				     each_ref_entry_fn fn, void *cb_data)
 {
 	int retval;
 	int i1 = 0, i2 = 0;

@@ -626,12 +637,10 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
 		struct ref_entry *e1, *e2;
 		int cmp;
 		if (i1 == dir1->nr) {
-			return do_for_each_ref_in_dir(dir2, i2,
-						      base, fn, trim, flags, cb_data);
+			return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
 		}
 		if (i2 == dir2->nr) {
-			return do_for_each_ref_in_dir(dir1, i1,
-						      base, fn, trim, flags, cb_data);
+			return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
 		}
 		e1 = dir1->entries[i1];
 		e2 = dir2->entries[i2];

@@ -643,14 +652,13 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
 				struct ref_dir *subdir2 = get_ref_dir(e2);
 				sort_ref_dir(subdir1);
 				sort_ref_dir(subdir2);
-				retval = do_for_each_ref_in_dirs(
-						subdir1, subdir2,
-						base, fn, trim, flags, cb_data);
+				retval = do_for_each_entry_in_dirs(
+						subdir1, subdir2, fn, cb_data);
 				i1++;
 				i2++;
 			} else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
 				/* Both are references; ignore the one from dir1. */
-				retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
+				retval = fn(e2, cb_data);
 				i1++;
 				i2++;
 			} else {

@@ -669,11 +677,10 @@ static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
 			if (e->flag & REF_DIR) {
 				struct ref_dir *subdir = get_ref_dir(e);
 				sort_ref_dir(subdir);
-				retval = do_for_each_ref_in_dir(
-						subdir, 0,
-						base, fn, trim, flags, cb_data);
+				retval = do_for_each_entry_in_dir(
+						subdir, 0, fn, cb_data);
 			} else {
-				retval = do_one_ref(base, fn, trim, flags, cb_data, e);
+				retval = fn(e, cb_data);
 			}
 		}
 		if (retval)

@@ -702,14 +709,13 @@ struct name_conflict_cb {
 	const char *conflicting_refname;
 };
 
-static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
-			    int flags, void *cb_data)
+static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
 {
 	struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
-	if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
+	if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
 		return 0;
-	if (names_conflict(data->refname, existingrefname)) {
-		data->conflicting_refname = existingrefname;
+	if (names_conflict(data->refname, entry->name)) {
+		data->conflicting_refname = entry->name;
 		return 1;
 	}
 	return 0;

@@ -717,7 +723,7 @@ static int name_conflict_fn(const char *existingrefname, const unsigned char *sh
 
 /*
  * Return true iff a reference named refname could be created without
- * conflicting with the name of an existing reference in array.  If
+ * conflicting with the name of an existing reference in dir.  If
  * oldrefname is non-NULL, ignore potential conflicts with oldrefname
  * (e.g., because oldrefname is scheduled for deletion in the same
  * operation).

@@ -731,9 +737,7 @@ static int is_refname_available(const char *refname, const char *oldrefname,
 	data.conflicting_refname = NULL;
 
 	sort_ref_dir(dir);
-	if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
-				   0, DO_FOR_EACH_INCLUDE_BROKEN,
-				   &data)) {
+	if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
 		error("'%s' exists; cannot create '%s'",
 		      data.conflicting_refname, refname);
 		return 0;

@@ -1421,14 +1425,12 @@ void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 }
 
 /*
- * Call fn for each reference in the specified submodule for which the
- * refname begins with base.  If trim is non-zero, then trim that many
- * characters off the beginning of each refname before passing the
- * refname to fn.  flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
- * broken references in the iteration.
+ * Call fn for each reference in the specified submodule, omitting
+ * references not in the containing_dir of base.  fn is called for all
+ * references, including broken ones.
  */
-static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
-			   int trim, int flags, void *cb_data)
+static int do_for_each_entry(const char *submodule, const char *base,
+			     each_ref_entry_fn fn, void *cb_data)
 {
 	struct ref_cache *refs = get_ref_cache(submodule);
 	struct ref_dir *packed_dir = get_packed_refs(refs);

@@ -1443,24 +1445,41 @@ static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn
 	if (packed_dir && loose_dir) {
 		sort_ref_dir(packed_dir);
 		sort_ref_dir(loose_dir);
-		retval = do_for_each_ref_in_dirs(
-				packed_dir, loose_dir,
-				base, fn, trim, flags, cb_data);
+		retval = do_for_each_entry_in_dirs(
+				packed_dir, loose_dir, fn, cb_data);
 	} else if (packed_dir) {
 		sort_ref_dir(packed_dir);
-		retval = do_for_each_ref_in_dir(
-				packed_dir, 0,
-				base, fn, trim, flags, cb_data);
+		retval = do_for_each_entry_in_dir(
+				packed_dir, 0, fn, cb_data);
 	} else if (loose_dir) {
 		sort_ref_dir(loose_dir);
-		retval = do_for_each_ref_in_dir(
-				loose_dir, 0,
-				base, fn, trim, flags, cb_data);
+		retval = do_for_each_entry_in_dir(
+				loose_dir, 0, fn, cb_data);
 	}
 
 	return retval;
 }
 
+/*
+ * Call fn for each reference in the specified submodule for which the
+ * refname begins with base.  If trim is non-zero, then trim that many
+ * characters off the beginning of each refname before passing the
+ * refname to fn.  flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
+ * broken references in the iteration.
+ */
+static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
+			   int trim, int flags, void *cb_data)
+{
+	struct ref_entry_cb data;
+	data.base = base;
+	data.trim = trim;
+	data.flags = flags;
+	data.fn = fn;
+	data.cb_data = cb_data;
+
+	return do_for_each_entry(submodule, base, do_one_ref, &data);
+}
+
 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
 {
 	unsigned char sha1[20];

@@ -1870,20 +1889,21 @@ struct repack_without_ref_sb {
 	int fd;
 };
 
-static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
-				 int flags, void *cb_data)
+static int repack_without_ref_fn(struct ref_entry *entry, void *cb_data)
 {
 	struct repack_without_ref_sb *data = cb_data;
 	char line[PATH_MAX + 100];
 	int len;
 
-	if (!strcmp(data->refname, refname))
+	if (!strcmp(data->refname, entry->name))
 		return 0;
+	if (!ref_resolves_to_object(entry))
+		return 0; /* Skip broken refs */
 	len = snprintf(line, sizeof(line), "%s %s\n",
-		       sha1_to_hex(sha1), refname);
+		       sha1_to_hex(entry->u.value.sha1), entry->name);
 	/* this should not happen but just being defensive */
 	if (len > sizeof(line))
-		die("too long a refname '%s'", refname);
+		die("too long a refname '%s'", entry->name);
 	write_or_die(data->fd, line, len);
 	return 0;
 }

@@ -1907,7 +1927,7 @@ static int repack_without_ref(const char *refname)
 	}
 	clear_packed_ref_cache(refs);
 	packed = get_packed_refs(refs);
-	do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
+	do_for_each_entry_in_dir(packed, 0, repack_without_ref_fn, &data);
 	return commit_lock_file(&packlock);
 }
 

@@ -1286,6 +1286,16 @@ enum peel_status {
 
 	/* object cannot be peeled because it is not a tag: */
 	PEEL_NON_TAG = -2,
+
+	/* ref_entry contains no peeled value because it is a symref: */
+	PEEL_IS_SYMREF = -3,
+
+	/*
+	 * ref_entry cannot be peeled because it is broken (i.e., the
+	 * symbolic reference cannot even be resolved to an object
+	 * name):
+	 */
+	PEEL_BROKEN = -4,
 };
 
 /*

@@ -1317,31 +1327,56 @@ static enum peel_status peel_object(const unsigned char *name, unsigned char *sh
 	return PEEL_PEELED;
 }
 
+/*
+ * Peel the entry (if possible) and return its new peel_status.
+ */
+static enum peel_status peel_entry(struct ref_entry *entry)
+{
+	enum peel_status status;
+
+	if (entry->flag & REF_KNOWS_PEELED)
+		return is_null_sha1(entry->u.value.peeled) ?
+			PEEL_NON_TAG : PEEL_PEELED;
+	if (entry->flag & REF_ISBROKEN)
+		return PEEL_BROKEN;
+	if (entry->flag & REF_ISSYMREF)
+		return PEEL_IS_SYMREF;
+
+	status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
+	if (status == PEEL_PEELED || status == PEEL_NON_TAG)
+		entry->flag |= REF_KNOWS_PEELED;
+	return status;
+}
+
 int peel_ref(const char *refname, unsigned char *sha1)
 {
 	int flag;
 	unsigned char base[20];
 
 	if (current_ref && (current_ref->name == refname
-		|| !strcmp(current_ref->name, refname))) {
-		if (current_ref->flag & REF_KNOWS_PEELED) {
-			if (is_null_sha1(current_ref->u.value.peeled))
-			    return -1;
-			hashcpy(sha1, current_ref->u.value.peeled);
-			return 0;
-		}
-		return peel_object(current_ref->u.value.sha1, sha1);
+			    || !strcmp(current_ref->name, refname))) {
+		if (peel_entry(current_ref))
+			return -1;
+		hashcpy(sha1, current_ref->u.value.peeled);
+		return 0;
 	}
 
 	if (read_ref_full(refname, base, 1, &flag))
 		return -1;
 
-	if ((flag & REF_ISPACKED)) {
+	/*
+	 * If the reference is packed, read its ref_entry from the
+	 * cache in the hope that we already know its peeled value.
+	 * We only try this optimization on packed references because
+	 * (a) forcing the filling of the loose reference cache could
+	 * be expensive and (b) loose references anyway usually do not
+	 * have REF_KNOWS_PEELED.
+	 */
+	if (flag & REF_ISPACKED) {
 		struct ref_entry *r = get_packed_ref(refname);
-
-		if (r && (r->flag & REF_KNOWS_PEELED)) {
-			if (is_null_sha1(r->u.value.peeled))
-			    return -1;
+		if (r) {
+			if (peel_entry(r))
+				return -1;
 			hashcpy(sha1, r->u.value.peeled);
 			return 0;
 		}

@@ -531,15 +531,17 @@ static void sort_ref_dir(struct ref_dir *dir)
 
 /*
  * Return true iff the reference described by entry can be resolved to
- * an object in the database.  Emit a warning if the referred-to
- * object does not exist.
+ * an object in the database.  If report_errors is true, emit a
+ * warning if the referred-to object does not exist.
  */
-static int ref_resolves_to_object(struct ref_entry *entry)
+static int ref_resolves_to_object(struct ref_entry *entry, int report_errors)
 {
 	if (entry->flag & REF_ISBROKEN)
 		return 0;
 	if (!has_sha1_file(entry->u.value.sha1)) {
-		error("%s does not point to a valid object!", entry->name);
+		if (report_errors)
+			error("%s does not point to a valid object!",
+			      entry->name);
 		return 0;
 	}
 	return 1;

@@ -578,7 +580,7 @@ static int do_one_ref(struct ref_entry *entry, void *cb_data)
 		return 0;
 
 	if (!((data->flags & DO_FOR_EACH_INCLUDE_BROKEN) ||
-	      ref_resolves_to_object(entry)))
+	      ref_resolves_to_object(entry, 1)))
 		return 0;
 
 	current_ref = entry;

@@ -1897,8 +1899,9 @@ static int repack_without_ref_fn(struct ref_entry *entry, void *cb_data)
 
 	if (!strcmp(data->refname, entry->name))
 		return 0;
-	if (!ref_resolves_to_object(entry))
-		return 0; /* Skip broken refs */
+	/* Silently skip broken refs: */
+	if (!ref_resolves_to_object(entry, 0))
+		return 0;
 	len = snprintf(line, sizeof(line), "%s %s\n",
 		       sha1_to_hex(entry->u.value.sha1), entry->name);
 	/* this should not happen but just being defensive */

@@ -142,7 +142,7 @@ test_expect_success 'delete ref with dangling packed version' '
 	test_cmp /dev/null result
 '
 
-test_expect_failure 'delete ref while another dangling packed ref' '
+test_expect_success 'delete ref while another dangling packed ref' '
 	git branch lamb &&
 	git commit --allow-empty -m "future garbage" &&
 	git pack-refs --all &&

@@ -467,6 +467,57 @@ static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
 }
 
 /*
+ * Remove the entry with the given name from dir, recursing into
+ * subdirectories as necessary.  If refname is the name of a directory
+ * (i.e., ends with '/'), then remove the directory and its contents.
+ * If the removal was successful, return the number of entries
+ * remaining in the directory entry that contained the deleted entry.
+ * If the name was not found, return -1.  Please note that this
+ * function only deletes the entry from the cache; it does not delete
+ * it from the filesystem or ensure that other cache entries (which
+ * might be symbolic references to the removed entry) are updated.
+ * Nor does it remove any containing dir entries that might be made
+ * empty by the removal.  dir must represent the top-level directory
+ * and must already be complete.
+ */
+static int remove_entry(struct ref_dir *dir, const char *refname)
+{
+	int refname_len = strlen(refname);
+	int entry_index;
+	struct ref_entry *entry;
+	int is_dir = refname[refname_len - 1] == '/';
+	if (is_dir) {
+		/*
+		 * refname represents a reference directory.  Remove
+		 * the trailing slash; otherwise we will get the
+		 * directory *representing* refname rather than the
+		 * one *containing* it.
+		 */
+		char *dirname = xmemdupz(refname, refname_len - 1);
+		dir = find_containing_dir(dir, dirname, 0);
+		free(dirname);
+	} else {
+		dir = find_containing_dir(dir, refname, 0);
+	}
+	if (!dir)
+		return -1;
+	entry_index = search_ref_dir(dir, refname, refname_len);
+	if (entry_index == -1)
+		return -1;
+	entry = dir->entries[entry_index];
+
+	memmove(&dir->entries[entry_index],
+		&dir->entries[entry_index + 1],
+		(dir->nr - entry_index - 1) * sizeof(*dir->entries)
+		);
+	dir->nr--;
+	if (dir->sorted > entry_index)
+		dir->sorted--;
+	free_ref_entry(entry);
+	return dir->nr;
+}
+
+/*
  * Add a ref_entry to the ref_dir (unsorted), recursing into
  * subdirectories as necessary.  dir must represent the top-level
  * directory.  Return 0 on success.

@@ -1892,19 +1943,12 @@ struct ref_lock *lock_any_ref_for_update(const char *refname,
 	return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
 }
 
-struct repack_without_ref_sb {
-	const char *refname;
-	int fd;
-};
-
-static int repack_without_ref_fn(struct ref_entry *entry, void *cb_data)
+static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
 {
-	struct repack_without_ref_sb *data = cb_data;
+	int *fd = cb_data;
 	char line[PATH_MAX + 100];
 	int len;
 
-	if (!strcmp(data->refname, entry->name))
-		return 0;
 	/* Silently skip broken refs: */
 	if (!ref_resolves_to_object(entry, 0))
 		return 0;

@@ -1913,7 +1957,7 @@ static int repack_without_ref_fn(struct ref_entry *entry, void *cb_data)
 	/* this should not happen but just being defensive */
 	if (len > sizeof(line))
 		die("too long a refname '%s'", entry->name);
-	write_or_die(data->fd, line, len);
+	write_or_die(*fd, line, len);
 	return 0;
 }
 

@@ -1921,22 +1965,30 @@ static struct lock_file packlock;
 
 static int repack_without_ref(const char *refname)
 {
-	struct repack_without_ref_sb data;
+	int fd;
 	struct ref_cache *refs = get_ref_cache(NULL);
 	struct ref_dir *packed;
 
 	if (!get_packed_ref(refname))
 		return 0; /* refname does not exist in packed refs */
 
-	data.refname = refname;
-	data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
-	if (data.fd < 0) {
+	fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
+	if (fd < 0) {
 		unable_to_lock_error(git_path("packed-refs"), errno);
 		return error("cannot delete '%s' from packed refs", refname);
 	}
 	clear_packed_ref_cache(refs);
 	packed = get_packed_refs(refs);
-	do_for_each_entry_in_dir(packed, 0, repack_without_ref_fn, &data);
+	/* Remove refname from the cache. */
+	if (remove_entry(packed, refname) == -1) {
+		/*
+		 * The packed entry disappeared while we were
+		 * acquiring the lock.
+		 */
+		rollback_lock_file(&packlock);
+		return 0;
+	}
+	do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
 	return commit_lock_file(&packlock);
 }
 

@@ -1965,7 +2017,7 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 	ret |= repack_without_ref(lock->ref_name);
 
 	unlink_or_warn(git_path("logs/%s", lock->ref_name));
-	invalidate_ref_cache(NULL);
+	clear_loose_ref_cache(get_ref_cache(NULL));
 	unlock_ref(lock);
 	return ret;
 }

@@ -1956,29 +1956,43 @@ struct ref_lock *lock_any_ref_for_update(const char *refname,
 	return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
 }
 
-static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
+/*
+ * Write an entry to the packed-refs file for the specified refname.
+ * If peeled is non-NULL, write it as the entry's peeled value.
+ */
+static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
+			       unsigned char *peeled)
 {
-	int *fd = cb_data;
 	char line[PATH_MAX + 100];
 	int len;
 
-	/* Silently skip broken refs: */
-	if (!ref_resolves_to_object(entry, 0))
-		return 0;
 	len = snprintf(line, sizeof(line), "%s %s\n",
-		       sha1_to_hex(entry->u.value.sha1), entry->name);
+		       sha1_to_hex(sha1), refname);
 	/* this should not happen but just being defensive */
 	if (len > sizeof(line))
-		die("too long a refname '%s'", entry->name);
-	write_or_die(*fd, line, len);
-	if (!peel_entry(entry)) {
-		/* This reference could be peeled; write the peeled value: */
+		die("too long a refname '%s'", refname);
+	write_or_die(fd, line, len);
+
+	if (peeled) {
 		if (snprintf(line, sizeof(line), "^%s\n",
-			     sha1_to_hex(entry->u.value.peeled)) !=
-		    PEELED_LINE_LENGTH)
+			     sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
 			die("internal error");
-		write_or_die(*fd, line, PEELED_LINE_LENGTH);
+		write_or_die(fd, line, PEELED_LINE_LENGTH);
 	}
+}
+
+static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
+{
+	int *fd = cb_data;
+	enum peel_status peel_status;
+
+	/* Silently skip broken refs: */
+	if (!ref_resolves_to_object(entry, 0))
+		return 0;
+	peel_status = peel_entry(entry);
+	write_packed_entry(*fd, entry->name, entry->u.value.sha1,
+			   peel_status == PEEL_PEELED ?
+			   entry->u.value.peeled : NULL);
 
 	return 0;
 }

@@ -61,4 +61,13 @@ test_expect_success 'refs are peeled outside of refs/tags (old packed)' '
 	test_cmp expect actual
 '
 
+test_expect_failure 'peeled refs survive deletion of packed ref' '
+	git pack-refs --all &&
+	cp .git/packed-refs fully-peeled &&
+	git branch yadda &&
+	git pack-refs --all &&
+	git branch -d yadda &&
+	test_cmp fully-peeled .git/packed-refs
+'
+
 test_done

@@ -878,6 +878,13 @@ void invalidate_ref_cache(const char *submodule)
 #define PEELED_LINE_LENGTH 42
 
 /*
+ * The packed-refs header line that we write out.  Perhaps other
+ * traits will be added later.  The trailing space is required.
+ */
+static const char PACKED_REFS_HEADER[] =
+	"# pack-refs with: peeled fully-peeled \n";
+
+/*
  * Parse one line from a packed-refs file.  Write the SHA1 to sha1.
  * Return a pointer to the refname within the line (null-terminated),
  * or NULL if there was a problem.