From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 7 Dec 2020 11:07:35 +0000 (+0200)
Subject: lib: istream-error - Set max_buffer_size
X-Git-Tag: 2.3.14.rc1~228
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=103cb028e3843c147967ad722080bc66aea34809;p=thirdparty%2Fdovecot%2Fcore.git

lib: istream-error - Set max_buffer_size

Although nothing is actually read from the stream, some filter istreams
don't behave properly with max_buffer_size=0. Currently at least
istream-decrypt returns -2 for reads instead of -1.

Fixes:
Panic: file istream.c: line 320 (i_stream_read_memarea): assertion failed: (_stream->skip != _stream->pos)
---

diff --git a/src/lib/istream.c b/src/lib/istream.c
index 06fd93e8ca..09e15bf4ba 100644
--- a/src/lib/istream.c
+++ b/src/lib/istream.c
@@ -1224,6 +1224,10 @@ struct istream *i_stream_create_error(int stream_errno)
 	stream->istream.seekable = TRUE;
 	stream->istream.eof = TRUE;
 	stream->istream.stream_errno = stream_errno;
+	/* Nothing can ever actually be read from this stream, but set a
+	   reasonable max_buffer_size anyway since some filter istreams don't
+	   behave properly otherwise. */
+	stream->max_buffer_size = IO_BLOCK_SIZE;
 	i_stream_create(stream, NULL, -1, 0);
 	i_stream_set_name(&stream->istream, "(error)");
 	return &stream->istream;