From: Stephan Bosch <stephan@dovecot.fi>
Date: Wed, 13 Jul 2016 07:46:08 +0000 (+0200)
Subject: Calling i_stream_next_line() on a chain stream would sometimes erroneously use the... 
X-Git-Tag: 2.2.26~466
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b4796b3100ce0c93f43060c42f314445442c9d0e;p=thirdparty%2Fdovecot%2Fcore.git

Calling i_stream_next_line() on a chain stream would sometimes erroneously use the stream->w_buffer.

It used the wrong check to assess whether the w_buffer is usable.
The chain stream only uses the w_buffer when partial stream data needs to be merged. Otherwise, a parent stream's buffer is used directly. However, this does not mean that w_buffer will be NULL in that case, which is what i_stream_next_line() assumed.
---

diff --git a/src/lib/istream.c b/src/lib/istream.c
index aa95c1cb9d..3f914f5515 100644
--- a/src/lib/istream.c
+++ b/src/lib/istream.c
@@ -386,7 +386,7 @@ static char *i_stream_next_line_finish(struct istream_private *stream, size_t i)
 		stream->line_crlf = FALSE;
 	}
 
-	if (stream->w_buffer != NULL) {
+	if (stream->buffer == stream->w_buffer) {
 		/* modify the buffer directly */
 		stream->w_buffer[end] = '\0';
 		ret = (char *)stream->w_buffer + stream->skip;