From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Thu, 17 Nov 2016 23:23:13 +0000 (+0200)
Subject: lib-index: Fix detecting whether caller synced everything in mailbox.
X-Git-Tag: 2.2.27~110
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2aa182ac91d179b94923eae31941f688fb345736;p=thirdparty%2Fdovecot%2Fcore.git

lib-index: Fix detecting whether caller synced everything in mailbox.

When mailbox_index_sync_begin() was followed by _commit(), without _next()s
in the middle actually syncing the mailbox, the tail_offset was updated to
indicate that the mailbox was fully synced. Existing code didn't rely on
this, so it probably didn't break anything.

This code hasn't worked for a long time, because log_view is always read
fully to the end in _sync_begin().
---

diff --git a/src/lib-index/mail-index-sync.c b/src/lib-index/mail-index-sync.c
index 34a9c78c6b..739716e478 100644
--- a/src/lib-index/mail-index-sync.c
+++ b/src/lib-index/mail-index-sync.c
@@ -26,6 +26,7 @@ struct mail_index_sync_ctx {
 
 	unsigned int no_warning:1;
 	unsigned int seen_nonexternal_transactions:1;
+	unsigned int fully_synced:1;
 };
 
 static void mail_index_sync_add_expunge(struct mail_index_sync_ctx *ctx)
@@ -680,6 +681,7 @@ bool mail_index_sync_next(struct mail_index_sync_ctx *ctx,
 	if (i == count) {
 		if (next_i == UINT_MAX) {
 			/* nothing left in sync_list */
+			ctx->fully_synced = TRUE;
 			return FALSE;
 		}
                 ctx->next_uid = next_found_uid;
@@ -773,15 +775,17 @@ mail_index_sync_update_mailbox_offset(struct mail_index_sync_ctx *ctx)
 	uint32_t seq;
 	uoff_t offset;
 
-	if (!mail_transaction_log_view_is_last(ctx->view->log_view)) {
-		/* didn't sync everything */
+	if (!ctx->fully_synced) {
+		/* Everything wasn't synced. This usually means that syncing
+		   was used for locking and nothing was synced. Don't update
+		   tail offset. */
 		mail_transaction_log_view_get_prev_pos(ctx->view->log_view,
 						       &seq, &offset);
-	} else {
-		/* synced everything, but we might also have committed new
-		   transactions. include them also here. */
-		mail_transaction_log_get_head(ctx->index->log, &seq, &offset);
+		return;
 	}
+	/* synced everything, but we might also have committed new
+	   transactions. include them also here. */
+	mail_transaction_log_get_head(ctx->index->log, &seq, &offset);
 	mail_transaction_log_set_mailbox_sync_pos(ctx->index->log, seq, offset);
 
 	/* If tail offset has changed, make sure it gets written to