dovecot-2.2: mbox: Fixed corruption in some usage patterns.

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.2/rev/b6ea460e7cc4
changeset: 18679:b6ea460e7cc4
user:      Timo Sirainen <tss at iki.fi>
date:      Wed May 13 19:24:55 2015 +0300
description:
mbox: Fixed corruption in some usage patterns.
Something like:
 - first mail is being expunged
 - other mails are being rewritten and they get their space from the
   expunged mail
 - there's not enough space for the last mail to get space
 - we add more space
 - we'll now need to use up the space. We can't just decide to mark the
   mails dirty.

diffstat:

 src/lib-storage/index/mbox/mbox-sync.c |  6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diffs (16 lines):

diff -r 8973648dd361 -r b6ea460e7cc4 src/lib-storage/index/mbox/mbox-sync.c
--- a/src/lib-storage/index/mbox/mbox-sync.c	Wed May 13 17:16:21 2015 +0300
+++ b/src/lib-storage/index/mbox/mbox-sync.c	Wed May 13 19:24:55 2015 +0300
@@ -689,8 +689,10 @@
 		}
 	} else if (mail_ctx->need_rewrite) {
 		mbox_sync_update_header(mail_ctx);
-		if (sync_ctx->delay_writes) {
-			/* mark it dirty and do it later */
+		if (sync_ctx->delay_writes && sync_ctx->need_space_seq == 0) {
+			/* mark it dirty and do it later. we can't do this
+			   if we're in the middle of rewriting acquiring more
+			   space. */
 			mail_ctx->dirty = TRUE;
 			return 0;
 		}