>From 05dd32756c98df54c1a5169f8039dcafcfb45eac Mon Sep 17 00:00:00 2001
From: Pavel Raiskup <address@hidden>
Date: Mon, 17 Nov 2014 13:13:15 +0100
Subject: [PATCH 1/2] Fix unaligned archive corruption with --append

If a archive size is not a factor of --block-size, do not
backspace the archive of whole record_size.

* src/buffer.c (backspace_output): Seek back only to beginning of
the current record.
---
 src/buffer.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/buffer.c b/src/buffer.c
index a7d8971..5dd48f7 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1031,7 +1031,13 @@ backspace_output (void)
 
     /* Seek back to the beginning of this record and start writing there.  */
 
-    position -= record_size;
+    off_t bs = position % record_size;
+
+    if (!bs)
+      bs = record_size;
+
+    position -= bs;
+
     if (position < 0)
       position = 0;
     if (rmtlseek (archive, position, SEEK_SET) != position)
-- 
1.9.3