# HG changeset patch
# User Timo Sirainen <tss@iki.fi>
# Date 1369677794 -10800
# Node ID 967ef2a7fa6fdcbfe128ac9b278ded422a191ef5
# Parent  bd8ec99cf502ec0de6072afdc510e530ea93e062
dbox: Don't cache pop3.uidl|order unless index header indicates there are those.
They exist only when doing a migration, so it's pretty wasteful storing
"doesn't exist" for all other installations.

diff -r bd8ec99cf502 -r 967ef2a7fa6f src/doveadm/doveadm-dump-index.c
--- a/src/doveadm/doveadm-dump-index.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/doveadm/doveadm-dump-index.c	Mon May 27 21:03:14 2013 +0300
@@ -36,10 +36,14 @@
 struct sdbox_index_header {
 	uint32_t rebuild_count;
 	guid_128_t mailbox_guid;
+	uint8_t flags;
+	uint8_t unused[3];
 };
 struct mdbox_index_header {
 	uint32_t map_uid_validity;
 	guid_128_t mailbox_guid;
+	uint8_t flags;
+	uint8_t unused[3];
 };
 struct mdbox_mail_index_record {
 	uint32_t map_uid;
@@ -122,11 +126,18 @@
 				  const struct mail_index_ext *ext)
 {
 	const void *data;
+	void *buf;
 
 	if (strcmp(ext->name, MAIL_INDEX_EXT_KEYWORDS) == 0)
 		return;
 
+	/* add some padding, since we don't bother to handle undersized
+	   headers correctly */
+	buf = t_malloc0(ext->hdr_size + 128);
 	data = CONST_PTR_OFFSET(index->map->hdr_base, ext->hdr_offset);
+	memcpy(buf, data, ext->hdr_size);
+	data = buf;
+
 	if (strcmp(ext->name, "hdr-vsize") == 0) {
 		const struct index_vsize_header *hdr = data;
 
@@ -164,6 +175,7 @@
 		printf(" - map_uid_validity .. = %u\n", hdr->map_uid_validity);
 		printf(" - mailbox_guid ...... = %s\n",
 		       guid_128_to_string(hdr->mailbox_guid));
+		printf(" - flags ............. = 0x%x\n", hdr->flags);
 	} else if (strcmp(ext->name, "dbox-hdr") == 0) {
 		const struct sdbox_index_header *hdr = data;
 
@@ -171,6 +183,7 @@
 		printf(" - rebuild_count . = %u\n", hdr->rebuild_count);
 		printf(" - mailbox_guid .. = %s\n",
 		       guid_128_to_string(hdr->mailbox_guid));
+		printf(" - flags ......... = 0x%x\n", hdr->flags);
 	} else if (strcmp(ext->name, "modseq") == 0) {
 		const struct mail_index_modseq_header *hdr = data;
 
@@ -241,8 +254,9 @@
 		printf("record_offset = %u\n", ext->record_offset);
 		printf("record_size . = %u\n", ext->record_size);
 		printf("record_align  = %u\n", ext->record_align);
-		if (ext->hdr_size > 0)
+		if (ext->hdr_size > 0) T_BEGIN {
 			dump_extension_header(index, ext);
+		} T_END;
 	}
 }
 
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-common/dbox-save.c
--- a/src/lib-storage/index/dbox-common/dbox-save.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-common/dbox-save.c	Mon May 27 21:03:14 2013 +0300
@@ -163,10 +163,12 @@
 		i_assert(strchr(mdata->pop3_uidl, '\n') == NULL);
 		str_printfa(str, "%c%s\n", DBOX_METADATA_POP3_UIDL,
 			    mdata->pop3_uidl);
+		ctx->have_pop3_uidls = TRUE;
 	}
 	if (mdata->pop3_order != 0) {
 		str_printfa(str, "%c%u\n", DBOX_METADATA_POP3_ORDER,
 			    mdata->pop3_order);
+		ctx->have_pop3_orders = TRUE;
 	}
 
 	guid = mdata->guid;
@@ -193,3 +195,32 @@
 	str_append_c(str, '\n');
 	o_stream_nsend(output, str_data(str), str_len(str));
 }
+
+void dbox_save_update_header_flags(struct dbox_save_context *ctx,
+				   struct mail_index_view *sync_view,
+				   uint32_t ext_id,
+				   unsigned int flags_offset)
+{
+	const void *data;
+	size_t data_size;
+	uint8_t old_flags = 0, flags;
+
+	mail_index_get_header_ext(sync_view, ext_id, &data, &data_size);
+	if (flags_offset < data_size)
+		old_flags = *((const uint8_t *)data + flags_offset);
+	else {
+		/* grow old dbox header */
+		mail_index_ext_resize_hdr(ctx->trans, ext_id, flags_offset+1);
+	}
+
+	flags = old_flags;
+	if (ctx->have_pop3_uidls)
+		flags |= DBOX_INDEX_HEADER_FLAG_HAVE_POP3_UIDLS;
+	if (ctx->have_pop3_orders)
+		flags |= DBOX_INDEX_HEADER_FLAG_HAVE_POP3_ORDERS;
+	if (flags != old_flags) {
+		/* flags changed, update them */
+		mail_index_update_header_ext(ctx->trans, ext_id,
+					     flags_offset, &flags, 1);
+	}
+}
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-common/dbox-save.h
--- a/src/lib-storage/index/dbox-common/dbox-save.h	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-common/dbox-save.h	Mon May 27 21:03:14 2013 +0300
@@ -16,6 +16,8 @@
 
 	unsigned int failed:1;
 	unsigned int finished:1;
+	unsigned int have_pop3_uidls:1;
+	unsigned int have_pop3_orders:1;
 };
 
 void dbox_save_begin(struct dbox_save_context *ctx, struct istream *input);
@@ -29,4 +31,9 @@
 
 void dbox_save_add_to_index(struct dbox_save_context *ctx);
 
+void dbox_save_update_header_flags(struct dbox_save_context *ctx,
+				   struct mail_index_view *sync_view,
+				   uint32_t ext_id,
+				   unsigned int flags_offset);
+
 #endif
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-common/dbox-storage.c
--- a/src/lib-storage/index/dbox-common/dbox-storage.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-common/dbox-storage.c	Mon May 27 21:03:14 2013 +0300
@@ -336,3 +336,16 @@
 		return -1;
 	return 0;
 }
+
+bool dbox_header_have_flag(struct mailbox *box, uint32_t ext_id,
+			   unsigned int flags_offset, uint8_t flag)
+{
+	const void *data;
+	size_t data_size;
+	uint8_t flags = 0;
+
+	mail_index_get_header_ext(box->view, ext_id, &data, &data_size);
+	if (flags_offset < data_size)
+		flags = *((const uint8_t *)data + flags_offset);
+	return (flags & flag) != 0;
+}
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-common/dbox-storage.h
--- a/src/lib-storage/index/dbox-common/dbox-storage.h	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-common/dbox-storage.h	Mon May 27 21:03:14 2013 +0300
@@ -23,6 +23,13 @@
 /* Flag specifies if the message should be in primary or alternative storage */
 #define DBOX_INDEX_FLAG_ALT MAIL_INDEX_MAIL_FLAG_BACKEND
 
+enum dbox_index_header_flags {
+	/* messages' metadata contain POP3 UIDLs */
+	DBOX_INDEX_HEADER_FLAG_HAVE_POP3_UIDLS	= 0x01,
+	/* messages' metadata contain POP3 orders */
+	DBOX_INDEX_HEADER_FLAG_HAVE_POP3_ORDERS	= 0x02
+};
+
 struct dbox_storage_vfuncs {
 	/* dbox file has zero references now. it should be either freed or
 	   left open in case it's accessed again soon */
@@ -67,5 +74,7 @@
 int dbox_mailbox_create(struct mailbox *box,
 			const struct mailbox_update *update, bool directory);
 int dbox_verify_alt_storage(struct mailbox_list *list);
+bool dbox_header_have_flag(struct mailbox *box, uint32_t ext_id,
+			   unsigned int flags_offset, uint8_t flag);
 
 #endif
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-multi/mdbox-mail.c
--- a/src/lib-storage/index/dbox-multi/mdbox-mail.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-multi/mdbox-mail.c	Mon May 27 21:03:14 2013 +0300
@@ -21,6 +21,7 @@
 	struct mdbox_index_header hdr;
 	const void *data;
 	uint32_t uid, cur_map_uid_validity;
+	bool need_resize;
 
 	mail_index_lookup_ext(view, seq, mbox->ext_id, &data, NULL);
 	dbox_rec = data;
@@ -34,7 +35,7 @@
 	}
 
 	if (mbox->map_uid_validity == 0) {
-		if (mdbox_read_header(mbox, &hdr) < 0)
+		if (mdbox_read_header(mbox, &hdr, &need_resize) < 0)
 			return -1;
 		mbox->map_uid_validity = hdr.map_uid_validity;
 	}
@@ -190,9 +191,26 @@
 		*value_r = p_strdup_printf(mail->imail.mail.data_pool, "%u",
 					   refcount);
 		return 0;
+	case MAIL_FETCH_UIDL_BACKEND:
+		if (!dbox_header_have_flag(&mbox->box, mbox->hdr_ext_id,
+				offsetof(struct mdbox_index_header, flags),
+				DBOX_INDEX_HEADER_FLAG_HAVE_POP3_UIDLS)) {
+			*value_r = "";
+			return 0;
+		}
+		break;
+	case MAIL_FETCH_POP3_ORDER:
+		if (!dbox_header_have_flag(&mbox->box, mbox->hdr_ext_id,
+				offsetof(struct mdbox_index_header, flags),
+				DBOX_INDEX_HEADER_FLAG_HAVE_POP3_ORDERS)) {
+			*value_r = "";
+			return 0;
+		}
+		break;
 	default:
-		return dbox_mail_get_special(_mail, field, value_r);
+		break;
 	}
+	return dbox_mail_get_special(_mail, field, value_r);
 }
 
 static void
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-multi/mdbox-save.c
--- a/src/lib-storage/index/dbox-multi/mdbox-save.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-multi/mdbox-save.c	Mon May 27 21:03:14 2013 +0300
@@ -314,6 +314,10 @@
 		return -1;
 	}
 
+	/* update dbox header flags */
+	dbox_save_update_header_flags(&ctx->ctx, ctx->sync_ctx->sync_view,
+		ctx->mbox->hdr_ext_id, offsetof(struct mdbox_index_header, flags));
+
 	/* assign UIDs for new messages */
 	hdr = mail_index_get_header(ctx->sync_ctx->sync_view);
 	mail_index_append_finish_uids(ctx->ctx.trans, hdr->next_uid,
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c
--- a/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c	Mon May 27 21:03:14 2013 +0300
@@ -58,6 +58,9 @@
 	struct mailbox_list *default_list;
 
 	struct rebuild_msg_mailbox prev_msg;
+
+	unsigned int have_pop3_uidls:1;
+	unsigned int have_pop3_orders:1;
 };
 
 static struct mdbox_storage_rebuild_context *
@@ -126,6 +129,15 @@
 	return 0;
 }
 
+static void rebuild_scan_metadata(struct mdbox_storage_rebuild_context *ctx,
+				  struct dbox_file *file)
+{
+	if (dbox_file_metadata_get(file, DBOX_METADATA_POP3_UIDL) != NULL)
+		ctx->have_pop3_uidls = TRUE;
+	if (dbox_file_metadata_get(file, DBOX_METADATA_POP3_ORDER) != NULL)
+		ctx->have_pop3_orders = TRUE;
+}
+
 static int rebuild_file_mails(struct mdbox_storage_rebuild_context *ctx,
 			      struct dbox_file *file, uint32_t file_id)
 {
@@ -177,6 +189,7 @@
 			ret = 0;
 			break;
 		}
+		rebuild_scan_metadata(ctx, file);
 
 		rec = p_new(ctx->pool, struct mdbox_rebuild_msg, 1);
 		rec->file_id = file_id;
@@ -476,7 +489,8 @@
 	memcpy(hdr_r, data, I_MIN(data_size, sizeof(*hdr_r)));
 }
 
-static void mdbox_header_update(struct index_rebuild_context *rebuild_ctx,
+static void mdbox_header_update(struct mdbox_storage_rebuild_context *ctx,
+				struct index_rebuild_context *rebuild_ctx,
 				struct mdbox_mailbox *mbox)
 {
 	struct mdbox_index_header hdr, backup_hdr;
@@ -502,6 +516,11 @@
 	/* update map's uid-validity */
 	hdr.map_uid_validity = mdbox_map_get_uid_validity(mbox->storage->map);
 
+	if (ctx->have_pop3_uidls)
+		hdr.flags |= DBOX_INDEX_HEADER_FLAG_HAVE_POP3_UIDLS;
+	if (ctx->have_pop3_orders)
+		hdr.flags |= DBOX_INDEX_HEADER_FLAG_HAVE_POP3_ORDERS;
+
 	/* and write changes */
 	mail_index_update_header_ext(rebuild_ctx->trans, mbox->hdr_ext_id, 0,
 				     &hdr, sizeof(hdr));
@@ -545,7 +564,7 @@
 	}
 
 	rebuild_ctx = index_index_rebuild_init(&mbox->box, view, trans);
-	mdbox_header_update(rebuild_ctx, mbox);
+	mdbox_header_update(ctx, rebuild_ctx, mbox);
 	rebuild_mailbox_multi(ctx, rebuild_ctx, mbox, view, trans);
 	index_index_rebuild_deinit(&rebuild_ctx, dbox_get_uidvalidity_next);
 
@@ -643,6 +662,7 @@
 			mailbox = mailbox_list_get_vname(ctx->default_list, mailbox);
 			mailbox = t_strdup(mailbox);
 		}
+		rebuild_scan_metadata(ctx, file);
 	}
 	dbox_file_unref(&file);
 	if (ret <= 0 || deleted) {
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-multi/mdbox-storage.c
--- a/src/lib-storage/index/dbox-multi/mdbox-storage.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-multi/mdbox-storage.c	Mon May 27 21:03:14 2013 +0300
@@ -197,7 +197,7 @@
 }
 
 int mdbox_read_header(struct mdbox_mailbox *mbox,
-		      struct mdbox_index_header *hdr)
+		      struct mdbox_index_header *hdr, bool *need_resize_r)
 {
 	const void *data;
 	size_t data_size;
@@ -216,6 +216,7 @@
 	}
 	memset(hdr, 0, sizeof(*hdr));
 	memcpy(hdr, data, I_MIN(data_size, sizeof(*hdr)));
+	*need_resize_r = data_size < sizeof(*hdr);
 	return 0;
 }
 
@@ -224,8 +225,9 @@
 			 const struct mailbox_update *update)
 {
 	struct mdbox_index_header hdr, new_hdr;
+	bool need_resize;
 
-	if (mdbox_read_header(mbox, &hdr) < 0)
+	if (mdbox_read_header(mbox, &hdr, &need_resize) < 0)
 		memset(&hdr, 0, sizeof(hdr));
 
 	new_hdr = hdr;
@@ -239,6 +241,10 @@
 
 	new_hdr.map_uid_validity =
 		mdbox_map_get_uid_validity(mbox->storage->map);
+	if (need_resize) {
+		mail_index_ext_resize_hdr(trans, mbox->hdr_ext_id,
+					  sizeof(new_hdr));
+	}
 	if (memcmp(&hdr, &new_hdr, sizeof(hdr)) != 0) {
 		mail_index_update_header_ext(trans, mbox->hdr_ext_id, 0,
 					     &new_hdr, sizeof(new_hdr));
@@ -365,14 +371,15 @@
 mdbox_mailbox_get_guid(struct mdbox_mailbox *mbox, guid_128_t guid_r)
 {
 	struct mdbox_index_header hdr;
+	bool need_resize;
 
-	if (mdbox_read_header(mbox, &hdr) < 0)
+	if (mdbox_read_header(mbox, &hdr, &need_resize) < 0)
 		memset(&hdr, 0, sizeof(hdr));
 
 	if (guid_128_is_empty(hdr.mailbox_guid)) {
 		/* regenerate it */
 		if (mdbox_write_index_header(&mbox->box, NULL, NULL) < 0 ||
-		    mdbox_read_header(mbox, &hdr) < 0)
+		    mdbox_read_header(mbox, &hdr, &need_resize) < 0)
 			return -1;
 	}
 	memcpy(guid_r, hdr.mailbox_guid, GUID_128_SIZE);
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-multi/mdbox-storage.h
--- a/src/lib-storage/index/dbox-multi/mdbox-storage.h	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-multi/mdbox-storage.h	Mon May 27 21:03:14 2013 +0300
@@ -17,6 +17,8 @@
 struct mdbox_index_header {
 	uint32_t map_uid_validity;
 	guid_128_t mailbox_guid;
+	uint8_t flags; /* enum dbox_index_header_flags */
+	uint8_t unused[3];
 };
 
 struct mdbox_storage {
@@ -69,7 +71,7 @@
 		      uint32_t seq, uint32_t *map_uid_r);
 uint32_t dbox_get_uidvalidity_next(struct mailbox_list *list);
 int mdbox_read_header(struct mdbox_mailbox *mbox,
-		      struct mdbox_index_header *hdr);
+		      struct mdbox_index_header *hdr, bool *need_resize_r);
 void mdbox_update_header(struct mdbox_mailbox *mbox,
 			 struct mail_index_transaction *trans,
 			 const struct mailbox_update *update) ATTR_NULL(3);
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-mail.c
--- a/src/lib-storage/index/dbox-single/sdbox-mail.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-mail.c	Mon May 27 21:03:14 2013 +0300
@@ -65,6 +65,7 @@
 sdbox_mail_get_special(struct mail *_mail, enum mail_fetch_field field,
 		       const char **value_r)
 {
+	struct sdbox_mailbox *mbox = (struct sdbox_mailbox *)_mail->box;
 	struct dbox_mail *mail = (struct dbox_mail *)_mail;
 	struct stat st;
 
@@ -82,9 +83,26 @@
 		*value_r = p_strdup_printf(mail->imail.mail.data_pool, "%lu",
 					   (unsigned long)st.st_nlink);
 		return 0;
+	case MAIL_FETCH_UIDL_BACKEND:
+		if (!dbox_header_have_flag(&mbox->box, mbox->hdr_ext_id,
+				offsetof(struct sdbox_index_header, flags),
+				DBOX_INDEX_HEADER_FLAG_HAVE_POP3_UIDLS)) {
+			*value_r = "";
+			return 0;
+		}
+		break;
+	case MAIL_FETCH_POP3_ORDER:
+		if (!dbox_header_have_flag(&mbox->box, mbox->hdr_ext_id,
+				offsetof(struct sdbox_index_header, flags),
+				DBOX_INDEX_HEADER_FLAG_HAVE_POP3_ORDERS)) {
+			*value_r = "";
+			return 0;
+		}
+		break;
 	default:
-		return dbox_mail_get_special(_mail, field, value_r);
+		break;
 	}
+	return dbox_mail_get_special(_mail, field, value_r);
 }
 
 int sdbox_mail_open(struct dbox_mail *mail, uoff_t *offset_r,
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-save.c
--- a/src/lib-storage/index/dbox-single/sdbox-save.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-save.c	Mon May 27 21:03:14 2013 +0300
@@ -289,6 +289,10 @@
 		return -1;
 	}
 
+	/* update dbox header flags */
+	dbox_save_update_header_flags(&ctx->ctx, ctx->sync_ctx->sync_view,
+		ctx->mbox->hdr_ext_id, offsetof(struct sdbox_index_header, flags));
+
 	/* assign UIDs for new messages */
 	hdr = mail_index_get_header(ctx->sync_ctx->sync_view);
 	mail_index_append_finish_uids(ctx->ctx.trans, hdr->next_uid,
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-storage.c
--- a/src/lib-storage/index/dbox-single/sdbox-storage.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-storage.c	Mon May 27 21:03:14 2013 +0300
@@ -138,7 +138,8 @@
 }
 
 int sdbox_read_header(struct sdbox_mailbox *mbox,
-		      struct sdbox_index_header *hdr, bool log_error)
+		      struct sdbox_index_header *hdr, bool log_error,
+		      bool *need_resize_r)
 {
 	struct mail_index_view *view;
 	const void *data;
@@ -173,6 +174,7 @@
 		}
 	}
 	mail_index_view_close(&view);
+	*need_resize_r = data_size < sizeof(*hdr);
 	return ret;
 }
 
@@ -181,8 +183,9 @@
 				const struct mailbox_update *update)
 {
 	struct sdbox_index_header hdr, new_hdr;
+	bool need_resize;
 
-	if (sdbox_read_header(mbox, &hdr, TRUE) < 0)
+	if (sdbox_read_header(mbox, &hdr, TRUE, &need_resize) < 0)
 		memset(&hdr, 0, sizeof(hdr));
 
 	new_hdr = hdr;
@@ -194,6 +197,10 @@
 		guid_128_generate(new_hdr.mailbox_guid);
 	}
 
+	if (need_resize) {
+		mail_index_ext_resize_hdr(trans, mbox->hdr_ext_id,
+					  sizeof(new_hdr));
+	}
 	if (memcmp(&hdr, &new_hdr, sizeof(hdr)) != 0) {
 		mail_index_update_header_ext(trans, mbox->hdr_ext_id, 0,
 					     &new_hdr, sizeof(new_hdr));
@@ -278,8 +285,10 @@
 {
 	struct sdbox_mailbox *mbox = (struct sdbox_mailbox *)box;
 	struct sdbox_index_header hdr;
+	bool need_resize;
 
-	if (sdbox_read_header(mbox, &hdr, TRUE) < 0 || hdr.rebuild_count == 0)
+	if (sdbox_read_header(mbox, &hdr, TRUE, &need_resize) < 0 ||
+	    hdr.rebuild_count == 0)
 		mbox->corrupted_rebuild_count = 1;
 	else
 		mbox->corrupted_rebuild_count = hdr.rebuild_count;
@@ -314,6 +323,7 @@
 {
 	struct sdbox_mailbox *mbox = (struct sdbox_mailbox *)box;
 	struct sdbox_index_header hdr;
+	bool need_resize;
 
 	if (sdbox_mailbox_alloc_index(mbox) < 0)
 		return -1;
@@ -332,17 +342,17 @@
 	}
 
 	/* get/generate mailbox guid */
-	if (sdbox_read_header(mbox, &hdr, FALSE) < 0) {
+	if (sdbox_read_header(mbox, &hdr, FALSE, &need_resize) < 0) {
 		/* looks like the mailbox is corrupted */
 		(void)sdbox_sync(mbox, SDBOX_SYNC_FLAG_FORCE);
-		if (sdbox_read_header(mbox, &hdr, TRUE) < 0)
+		if (sdbox_read_header(mbox, &hdr, TRUE, &need_resize) < 0)
 			memset(&hdr, 0, sizeof(hdr));
 	}
 
 	if (guid_128_is_empty(hdr.mailbox_guid)) {
 		/* regenerate it */
 		if (sdbox_mailbox_create_indexes(box, NULL, NULL) < 0 ||
-		    sdbox_read_header(mbox, &hdr, TRUE) < 0)
+		    sdbox_read_header(mbox, &hdr, TRUE, &need_resize) < 0)
 			return -1;
 	}
 	memcpy(mbox->mailbox_guid, hdr.mailbox_guid,
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-storage.h
--- a/src/lib-storage/index/dbox-single/sdbox-storage.h	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-storage.h	Mon May 27 21:03:14 2013 +0300
@@ -13,6 +13,8 @@
 	/* increased every time a full mailbox rebuild is done */
 	uint32_t rebuild_count;
 	guid_128_t mailbox_guid;
+	uint8_t flags; /* enum dbox_index_header_flags */
+	uint8_t unused[3];
 };
 
 struct sdbox_storage {
@@ -37,7 +39,8 @@
 		    struct dbox_file **file_r);
 
 int sdbox_read_header(struct sdbox_mailbox *mbox,
-		      struct sdbox_index_header *hdr, bool log_error);
+		      struct sdbox_index_header *hdr, bool log_error,
+		      bool *need_resize_r);
 void sdbox_set_mailbox_corrupted(struct mailbox *box);
 
 struct mail_save_context *
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-sync-rebuild.c
--- a/src/lib-storage/index/dbox-single/sdbox-sync-rebuild.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-sync-rebuild.c	Mon May 27 21:03:14 2013 +0300
@@ -140,8 +140,9 @@
 {
 	struct sdbox_mailbox *mbox = (struct sdbox_mailbox *)ctx->box;
 	struct sdbox_index_header hdr;
+	bool need_resize;
 
-	if (sdbox_read_header(mbox, &hdr, FALSE) < 0)
+	if (sdbox_read_header(mbox, &hdr, FALSE, &need_resize) < 0)
 		memset(&hdr, 0, sizeof(hdr));
 	if (guid_128_is_empty(hdr.mailbox_guid))
 		guid_128_generate(hdr.mailbox_guid);
@@ -187,9 +188,10 @@
 	struct mail_index_view *view;
 	struct mail_index_transaction *trans;
 	struct sdbox_index_header hdr;
+	bool need_resize;
 	int ret;
 
-	if (!force && sdbox_read_header(mbox, &hdr, FALSE) == 0) {
+	if (!force && sdbox_read_header(mbox, &hdr, FALSE, &need_resize) == 0) {
 		if (hdr.rebuild_count != mbox->corrupted_rebuild_count &&
 		    hdr.rebuild_count != 0) {
 			/* already rebuilt by someone else */
diff -r bd8ec99cf502 -r 967ef2a7fa6f src/lib-storage/index/dbox-single/sdbox-sync.c
--- a/src/lib-storage/index/dbox-single/sdbox-sync.c	Mon May 27 20:45:08 2013 +0300
+++ b/src/lib-storage/index/dbox-single/sdbox-sync.c	Mon May 27 21:03:14 2013 +0300
@@ -164,10 +164,11 @@
 {
 	struct mail_index_view *view;
 	struct sdbox_index_header hdr;
+	bool need_resize;
 	int ret;
 
 	view = mail_index_view_open(mbox->box.index);
-	ret = sdbox_read_header(mbox, &hdr, log_error);
+	ret = sdbox_read_header(mbox, &hdr, log_error, &need_resize);
 	mail_index_view_close(&view);
 
 	if (ret < 0 && retry) {