From: Aki Tuomi <aki.tuomi@dovecot.fi>
Date: Fri, 16 Mar 2018 11:39:40 +0000 (+0200)
Subject: istream-mail: Move pos back when bailing out on error
X-Git-Tag: 2.3.9~2124
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ba1a411211d59ad5dbbaa512d7403943f58aae92;p=thirdparty%2Fdovecot%2Fcore.git

istream-mail: Move pos back when bailing out on error

Fixes
Panic: file istream.c: line 276 (i_stream_read): assertion failed: ((_stream->pos - _stream->skip) == (prev_pos - prev_skip))
---

diff --git a/src/lib-storage/index/istream-mail.c b/src/lib-storage/index/istream-mail.c
index f21310f5d1..365f8c897e 100644
--- a/src/lib-storage/index/istream-mail.c
+++ b/src/lib-storage/index/istream-mail.c
@@ -122,6 +122,9 @@ i_stream_mail_read(struct istream_private *stream)
 		}
 		if (mstream->expected_size < stream->istream.v_offset + size) {
 			i_stream_mail_set_size_corrupted(mstream, size);
+			/* istream code expects that the position has not changed
+			   when read error occurs, so move pos back. */
+			stream->pos -= size;
 			return -1;
 		}
 	} else if (ret == -1 && stream->istream.eof) {