1 files changed, 272 insertions, 137 deletions

diff --git a/refs.c b/refs.c
index 5ff457ebfc..ab2f2a92cd 100644
--- a/refs.c
+++ b/refs.c
@@ -6,6 +6,15 @@
 #include "dir.h"
 #include "string-list.h"
 
+struct ref_lock {
+	char *ref_name;
+	char *orig_ref_name;
+	struct lock_file *lk;
+	unsigned char old_sha1[20];
+	int lock_fd;
+	int force_write;
+};
+
 /*
  * How to handle various characters in refnames:
  * 0: An acceptable character for refs
@@ -1068,8 +1077,10 @@ static const char PACKED_REFS_HEADER[] =
  * Return a pointer to the refname within the line (null-terminated),
  * or NULL if there was a problem.
  */
-static const char *parse_ref_line(char *line, unsigned char *sha1)
+static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
 {
+	const char *ref;
+
 	/*
 	 * 42: the answer to everything.
 	 *
@@ -1078,22 +1089,23 @@ static const char *parse_ref_line(char *line, unsigned char *sha1)
 	 *  +1 (space in between hex and name)
 	 *  +1 (newline at the end of the line)
 	 */
-	int len = strlen(line) - 42;
-
-	if (len <= 0)
+	if (line->len <= 42)
 		return NULL;
-	if (get_sha1_hex(line, sha1) < 0)
+
+	if (get_sha1_hex(line->buf, sha1) < 0)
 		return NULL;
-	if (!isspace(line[40]))
+	if (!isspace(line->buf[40]))
 		return NULL;
-	line += 41;
-	if (isspace(*line))
+
+	ref = line->buf + 41;
+	if (isspace(*ref))
 		return NULL;
-	if (line[len] != '\n')
+
+	if (line->buf[line->len - 1] != '\n')
 		return NULL;
-	line[len] = 0;
+	line->buf[--line->len] = 0;
 
-	return line;
+	return ref;
 }
 
 /*
@@ -1126,16 +1138,15 @@ static const char *parse_ref_line(char *line, unsigned char *sha1)
 static void read_packed_refs(FILE *f, struct ref_dir *dir)
 {
 	struct ref_entry *last = NULL;
-	char refline[PATH_MAX];
+	struct strbuf line = STRBUF_INIT;
 	enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
 
-	while (fgets(refline, sizeof(refline), f)) {
+	while (strbuf_getwholeline(&line, f, '\n') != EOF) {
 		unsigned char sha1[20];
 		const char *refname;
-		static const char header[] = "# pack-refs with:";
+		const char *traits;
 
-		if (!strncmp(refline, header, sizeof(header)-1)) {
-			const char *traits = refline + sizeof(header) - 1;
+		if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
 			if (strstr(traits, " fully-peeled "))
 				peeled = PEELED_FULLY;
 			else if (strstr(traits, " peeled "))
@@ -1144,7 +1155,7 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
 			continue;
 		}
 
-		refname = parse_ref_line(refline, sha1);
+		refname = parse_ref_line(&line, sha1);
 		if (refname) {
 			int flag = REF_ISPACKED;
 
@@ -1160,10 +1171,10 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
 			continue;
 		}
 		if (last &&
-		    refline[0] == '^' &&
-		    strlen(refline) == PEELED_LINE_LENGTH &&
-		    refline[PEELED_LINE_LENGTH - 1] == '\n' &&
-		    !get_sha1_hex(refline + 1, sha1)) {
+		    line.buf[0] == '^' &&
+		    line.len == PEELED_LINE_LENGTH &&
+		    line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
+		    !get_sha1_hex(line.buf + 1, sha1)) {
 			hashcpy(last->u.value.peeled, sha1);
 			/*
 			 * Regardless of what the file header said,
@@ -1173,6 +1184,8 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
 			last->flag |= REF_KNOWS_PEELED;
 		}
 	}
+
+	strbuf_release(&line);
 }
 
 /*
@@ -1614,8 +1627,7 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
 
 char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)
 {
-	const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags);
-	return ret ? xstrdup(ret) : NULL;
+	return xstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags));
 }
 
 /* The argument to filter_refs */
@@ -2090,6 +2102,16 @@ int refname_match(const char *abbrev_name, const char *full_name)
 	return 0;
 }
 
+static void unlock_ref(struct ref_lock *lock)
+{
+	/* Do not free lock->lk -- atexit() still looks at them */
+	if (lock->lk)
+		rollback_lock_file(lock->lk);
+	free(lock->ref_name);
+	free(lock->orig_ref_name);
+	free(lock);
+}
+
 /* This function should make sure errno is meaningful on error */
 static struct ref_lock *verify_lock(struct ref_lock *lock,
 	const unsigned char *old_sha1, int mustexist)
@@ -2318,6 +2340,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 
 	lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
 	if (lock->lock_fd < 0) {
+		last_errno = errno;
 		if (errno == ENOENT && --attempts_remaining > 0)
 			/*
 			 * Maybe somebody just deleted one of the
@@ -2325,8 +2348,13 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 			 * again:
 			 */
 			goto retry;
-		else
-			unable_to_lock_die(ref_file, errno);
+		else {
+			struct strbuf err = STRBUF_INIT;
+			unable_to_lock_message(ref_file, errno, &err);
+			error("%s", err.buf);
+			strbuf_release(&err);
+			goto error_return;
+		}
 	}
 	return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 
@@ -2336,13 +2364,6 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	return NULL;
 }
 
-struct ref_lock *lock_any_ref_for_update(const char *refname,
-					 const unsigned char *old_sha1,
-					 int flags, int *type_p)
-{
-	return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);
-}
-
 /*
  * 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.
@@ -2639,22 +2660,25 @@ static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
 	return 0;
 }
 
-int repack_without_refs(const char **refnames, int n, struct strbuf *err)
+int repack_without_refs(struct string_list *refnames, struct strbuf *err)
 {
 	struct ref_dir *packed;
 	struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
-	struct string_list_item *ref_to_delete;
-	int i, ret, removed = 0;
+	struct string_list_item *refname, *ref_to_delete;
+	int ret, needs_repacking = 0, removed = 0;
 
 	assert(err);
 
 	/* Look for a packed ref */
-	for (i = 0; i < n; i++)
-		if (get_packed_ref(refnames[i]))
+	for_each_string_list_item(refname, refnames) {
+		if (get_packed_ref(refname->string)) {
+			needs_repacking = 1;
 			break;
+		}
+	}
 
 	/* Avoid locking if we have nothing to do */
-	if (i == n)
+	if (!needs_repacking)
 		return 0; /* no refname exists in packed refs */
 
 	if (lock_packed_refs(0)) {
@@ -2664,8 +2688,8 @@ int repack_without_refs(const char **refnames, int n, struct strbuf *err)
 	packed = get_packed_refs(&ref_cache);
 
 	/* Remove refnames from the cache */
-	for (i = 0; i < n; i++)
-		if (remove_entry(packed, refnames[i]) != -1)
+	for_each_string_list_item(refname, refnames)
+		if (remove_entry(packed, refname->string) != -1)
 			removed = 1;
 	if (!removed) {
 		/*
@@ -2888,7 +2912,7 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 	return 1;
 }
 
-int close_ref(struct ref_lock *lock)
+static int close_ref(struct ref_lock *lock)
 {
 	if (close_lock_file(lock->lk))
 		return -1;
@@ -2896,7 +2920,7 @@ int close_ref(struct ref_lock *lock)
 	return 0;
 }
 
-int commit_ref(struct ref_lock *lock)
+static int commit_ref(struct ref_lock *lock)
 {
 	if (commit_lock_file(lock->lk))
 		return -1;
@@ -2904,16 +2928,6 @@ int commit_ref(struct ref_lock *lock)
 	return 0;
 }
 
-void unlock_ref(struct ref_lock *lock)
-{
-	/* Do not free lock->lk -- atexit() still looks at them */
-	if (lock->lk)
-		rollback_lock_file(lock->lk);
-	free(lock->ref_name);
-	free(lock->orig_ref_name);
-	free(lock);
-}
-
 /*
  * copy the reflog message msg to buf, which has been allocated sufficiently
  * large, while cleaning up the whitespaces.  Especially, convert LF to space,
@@ -2990,15 +3004,37 @@ int log_ref_setup(const char *refname, char *logfile, int bufsize)
 	return 0;
 }
 
+static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
+			    const unsigned char *new_sha1,
+			    const char *committer, const char *msg)
+{
+	int msglen, written;
+	unsigned maxlen, len;
+	char *logrec;
+
+	msglen = msg ? strlen(msg) : 0;
+	maxlen = strlen(committer) + msglen + 100;
+	logrec = xmalloc(maxlen);
+	len = sprintf(logrec, "%s %s %s\n",
+		      sha1_to_hex(old_sha1),
+		      sha1_to_hex(new_sha1),
+		      committer);
+	if (msglen)
+		len += copy_msg(logrec + len - 1, msg) - 1;
+
+	written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
+	free(logrec);
+	if (written != len)
+		return -1;
+
+	return 0;
+}
+
 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
 			 const unsigned char *new_sha1, const char *msg)
 {
-	int logfd, result, written, oflags = O_APPEND | O_WRONLY;
-	unsigned maxlen, len;
-	int msglen;
+	int logfd, result, oflags = O_APPEND | O_WRONLY;
 	char log_file[PATH_MAX];
-	char *logrec;
-	const char *committer;
 
 	if (log_all_ref_updates < 0)
 		log_all_ref_updates = !is_bare_repository();
@@ -3010,19 +3046,9 @@ static int log_ref_write(const char *refname, const unsigned char *old_sha1,
 	logfd = open(log_file, oflags);
 	if (logfd < 0)
 		return 0;
-	msglen = msg ? strlen(msg) : 0;
-	committer = git_committer_info(0);
-	maxlen = strlen(committer) + msglen + 100;
-	logrec = xmalloc(maxlen);
-	len = sprintf(logrec, "%s %s %s\n",
-		      sha1_to_hex(old_sha1),
-		      sha1_to_hex(new_sha1),
-		      committer);
-	if (msglen)
-		len += copy_msg(logrec + len - 1, msg) - 1;
-	written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
-	free(logrec);
-	if (written != len) {
+	result = log_ref_write_fd(logfd, old_sha1, new_sha1,
+				  git_committer_info(0), msg);
+	if (result) {
 		int save_errno = errno;
 		close(logfd);
 		error("Unable to append to %s", log_file);
@@ -3404,29 +3430,54 @@ int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void
 
 			bp = find_beginning_of_line(buf, scanp);
 
-			if (*bp != '\n') {
-				strbuf_splice(&sb, 0, 0, buf, endp - buf);
-				if (pos)
-					break; /* need to fill another block */
-				scanp = buf - 1; /* leave loop */
-			} else {
+			if (*bp == '\n') {
 				/*
-				 * (bp + 1) thru endp is the beginning of the
-				 * current line we have in sb
+				 * The newline is the end of the previous line,
+				 * so we know we have complete line starting
+				 * at (bp + 1). Prefix it onto any prior data
+				 * we collected for the line and process it.
 				 */
 				strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
 				scanp = bp;
 				endp = bp + 1;
+				ret = show_one_reflog_ent(&sb, fn, cb_data);
+				strbuf_reset(&sb);
+				if (ret)
+					break;
+			} else if (!pos) {
+				/*
+				 * We are at the start of the buffer, and the
+				 * start of the file; there is no previous
+				 * line, and we have everything for this one.
+				 * Process it, and we can end the loop.
+				 */
+				strbuf_splice(&sb, 0, 0, buf, endp - buf);
+				ret = show_one_reflog_ent(&sb, fn, cb_data);
+				strbuf_reset(&sb);
+				break;
 			}
-			ret = show_one_reflog_ent(&sb, fn, cb_data);
-			strbuf_reset(&sb);
-			if (ret)
+
+			if (bp == buf) {
+				/*
+				 * We are at the start of the buffer, and there
+				 * is more file to read backwards. Which means
+				 * we are in the middle of a line. Note that we
+				 * may get here even if *bp was a newline; that
+				 * just means we are at the exact end of the
+				 * previous line, rather than some spot in the
+				 * middle.
+				 *
+				 * Save away what we have to be combined with
+				 * the data from the next read.
+				 */
+				strbuf_splice(&sb, 0, 0, buf, endp - buf);
 				break;
+			}
 		}
 
 	}
 	if (!ret && sb.len)
-		ret = show_one_reflog_ent(&sb, fn, cb_data);
+		die("BUG: reverse reflog parser had leftover data");
 
 	fclose(logfp);
 	strbuf_release(&sb);
@@ -3623,31 +3674,8 @@ int ref_transaction_create(struct ref_transaction *transaction,
 			   int flags, const char *msg,
 			   struct strbuf *err)
 {
-	struct ref_update *update;
-
-	assert(err);
-
-	if (transaction->state != REF_TRANSACTION_OPEN)
-		die("BUG: create called for transaction that is not open");
-
-	if (!new_sha1 || is_null_sha1(new_sha1))
-		die("BUG: create ref with null new_sha1");
-
-	if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
-		strbuf_addf(err, "refusing to create ref with bad name %s",
-			    refname);
-		return -1;
-	}
-
-	update = add_update(transaction, refname);
-
-	hashcpy(update->new_sha1, new_sha1);
-	hashclr(update->old_sha1);
-	update->flags = flags;
-	update->have_old = 1;
-	if (msg)
-		update->msg = xstrdup(msg);
-	return 0;
+	return ref_transaction_update(transaction, refname, new_sha1,
+				      null_sha1, flags, 1, msg, err);
 }
 
 int ref_transaction_delete(struct ref_transaction *transaction,
@@ -3656,26 +3684,8 @@ int ref_transaction_delete(struct ref_transaction *transaction,
 			   int flags, int have_old, const char *msg,
 			   struct strbuf *err)
 {
-	struct ref_update *update;
-
-	assert(err);
-
-	if (transaction->state != REF_TRANSACTION_OPEN)
-		die("BUG: delete called for transaction that is not open");
-
-	if (have_old && !old_sha1)
-		die("BUG: have_old is true but old_sha1 is NULL");
-
-	update = add_update(transaction, refname);
-	update->flags = flags;
-	update->have_old = have_old;
-	if (have_old) {
-		assert(!is_null_sha1(old_sha1));
-		hashcpy(update->old_sha1, old_sha1);
-	}
-	if (msg)
-		update->msg = xstrdup(msg);
-	return 0;
+	return ref_transaction_update(transaction, refname, null_sha1,
+				      old_sha1, flags, have_old, msg, err);
 }
 
 int update_ref(const char *action, const char *refname,
@@ -3738,10 +3748,11 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
 int ref_transaction_commit(struct ref_transaction *transaction,
 			   struct strbuf *err)
 {
-	int ret = 0, delnum = 0, i;
-	const char **delnames;
+	int ret = 0, i;
 	int n = transaction->nr;
 	struct ref_update **updates = transaction->updates;
+	struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
+	struct string_list_item *ref_to_delete;
 
 	assert(err);
 
@@ -3753,9 +3764,6 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 		return 0;
 	}
 
-	/* Allocate work space */
-	delnames = xmalloc(sizeof(*delnames) * n);
-
 	/* Copy, sort, and reject duplicate refs */
 	qsort(updates, n, sizeof(*updates), ref_update_compare);
 	if (ref_update_reject_duplicates(updates, n, err)) {
@@ -3815,16 +3823,17 @@ int ref_transaction_commit(struct ref_transaction *transaction,
 			}
 
 			if (!(update->flags & REF_ISPRUNING))
-				delnames[delnum++] = update->lock->ref_name;
+				string_list_append(&refs_to_delete,
+						   update->lock->ref_name);
 		}
 	}
 
-	if (repack_without_refs(delnames, delnum, err)) {
+	if (repack_without_refs(&refs_to_delete, err)) {
 		ret = TRANSACTION_GENERIC_ERROR;
 		goto cleanup;
 	}
-	for (i = 0; i < delnum; i++)
-		unlink_or_warn(git_path("logs/%s", delnames[i]));
+	for_each_string_list_item(ref_to_delete, &refs_to_delete)
+		unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
 	clear_loose_ref_cache(&ref_cache);
 
 cleanup:
@@ -3833,7 +3842,7 @@ cleanup:
 	for (i = 0; i < n; i++)
 		if (updates[i]->lock)
 			unlock_ref(updates[i]->lock);
-	free(delnames);
+	string_list_clear(&refs_to_delete, 0);
 	return ret;
 }
 
@@ -3972,3 +3981,129 @@ int ref_is_hidden(const char *refname)
 	}
 	return 0;
 }
+
+struct expire_reflog_cb {
+	unsigned int flags;
+	reflog_expiry_should_prune_fn *should_prune_fn;
+	void *policy_cb;
+	FILE *newlog;
+	unsigned char last_kept_sha1[20];
+};
+
+static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
+			     const char *email, unsigned long timestamp, int tz,
+			     const char *message, void *cb_data)
+{
+	struct expire_reflog_cb *cb = cb_data;
+	struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
+
+	if (cb->flags & EXPIRE_REFLOGS_REWRITE)
+		osha1 = cb->last_kept_sha1;
+
+	if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
+				   message, policy_cb)) {
+		if (!cb->newlog)
+			printf("would prune %s", message);
+		else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
+			printf("prune %s", message);
+	} else {
+		if (cb->newlog) {
+			fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
+				sha1_to_hex(osha1), sha1_to_hex(nsha1),
+				email, timestamp, tz, message);
+			hashcpy(cb->last_kept_sha1, nsha1);
+		}
+		if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
+			printf("keep %s", message);
+	}
+	return 0;
+}
+
+int reflog_expire(const char *refname, const unsigned char *sha1,
+		 unsigned int flags,
+		 reflog_expiry_prepare_fn prepare_fn,
+		 reflog_expiry_should_prune_fn should_prune_fn,
+		 reflog_expiry_cleanup_fn cleanup_fn,
+		 void *policy_cb_data)
+{
+	static struct lock_file reflog_lock;
+	struct expire_reflog_cb cb;
+	struct ref_lock *lock;
+	char *log_file;
+	int status = 0;
+
+	memset(&cb, 0, sizeof(cb));
+	cb.flags = flags;
+	cb.policy_cb = policy_cb_data;
+	cb.should_prune_fn = should_prune_fn;
+
+	/*
+	 * The reflog file is locked by holding the lock on the
+	 * reference itself, plus we might need to update the
+	 * reference if --updateref was specified:
+	 */
+	lock = lock_ref_sha1_basic(refname, sha1, NULL, 0, NULL);
+	if (!lock)
+		return error("cannot lock ref '%s'", refname);
+	if (!reflog_exists(refname)) {
+		unlock_ref(lock);
+		return 0;
+	}
+
+	log_file = git_pathdup("logs/%s", refname);
+	if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
+		/*
+		 * Even though holding $GIT_DIR/logs/$reflog.lock has
+		 * no locking implications, we use the lock_file
+		 * machinery here anyway because it does a lot of the
+		 * work we need, including cleaning up if the program
+		 * exits unexpectedly.
+		 */
+		if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
+			struct strbuf err = STRBUF_INIT;
+			unable_to_lock_message(log_file, errno, &err);
+			error("%s", err.buf);
+			strbuf_release(&err);
+			goto failure;
+		}
+		cb.newlog = fdopen_lock_file(&reflog_lock, "w");
+		if (!cb.newlog) {
+			error("cannot fdopen %s (%s)",
+			      reflog_lock.filename.buf, strerror(errno));
+			goto failure;
+		}
+	}
+
+	(*prepare_fn)(refname, sha1, cb.policy_cb);
+	for_each_reflog_ent(refname, expire_reflog_ent, &cb);
+	(*cleanup_fn)(cb.policy_cb);
+
+	if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
+		if (close_lock_file(&reflog_lock)) {
+			status |= error("couldn't write %s: %s", log_file,
+					strerror(errno));
+		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) &&
+			(write_in_full(lock->lock_fd,
+				sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
+			 write_str_in_full(lock->lock_fd, "\n") != 1 ||
+			 close_ref(lock) < 0)) {
+			status |= error("couldn't write %s",
+					lock->lk->filename.buf);
+			rollback_lock_file(&reflog_lock);
+		} else if (commit_lock_file(&reflog_lock)) {
+			status |= error("unable to commit reflog '%s' (%s)",
+					log_file, strerror(errno));
+		} else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
+			status |= error("couldn't set %s", lock->ref_name);
+		}
+	}
+	free(log_file);
+	unlock_ref(lock);
+	return status;
+
+ failure:
+	rollback_lock_file(&reflog_lock);
+	free(log_file);
+	unlock_ref(lock);
+	return -1;
+}