From: Timo Sirainen <tss@iki.fi>
Date: Thu, 2 Jul 2015 09:06:04 +0000 (+0200)
Subject: mdbox: Make sure rebuilding doesn't try to add a copy of the message too many times.
X-Git-Tag: 2.2.19.rc1~295
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c5c244da999da01465faea813031c96f96ff1c9f;p=thirdparty%2Fdovecot%2Fcore.git

mdbox: Make sure rebuilding doesn't try to add a copy of the message too many times.
Currently it just silently overflowed the 16bit refcount, which caused
problems later.
---

diff --git a/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c b/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c
index 43090ca05c..3ccc15b956 100644
--- a/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c
+++ b/src/lib-storage/index/dbox-multi/mdbox-storage-rebuild.c
@@ -20,6 +20,8 @@
 #include <dirent.h>
 #include <unistd.h>
 
+#define REBUILD_MAX_REFCOUNT 32768
+
 struct mdbox_rebuild_msg {
 	struct mdbox_rebuild_msg *guid_hash_next;
 
@@ -458,7 +460,8 @@ rebuild_mailbox_multi(struct mdbox_storage_rebuild_context *ctx,
 			   GUID exists multiple times */
 		}
 
-		if (rec != NULL) T_BEGIN {
+		if (rec != NULL &&
+		    rec->refcount < REBUILD_MAX_REFCOUNT) T_BEGIN {
 			/* keep this message. add it to mailbox index. */
 			i_assert(map_uid != 0);
 			rec->refcount++;
@@ -758,6 +761,7 @@ static int rebuild_restore_msg(struct mdbox_storage_rebuild_context *ctx,
 	mail_index_update_ext(ctx->prev_msg.trans, seq, mbox->guid_ext_id,
 			      msg->guid_128, NULL);
 
+	i_assert(msg->refcount == 0);
 	msg->refcount++;
 	return 0;
 }