dovecot-2.0: istream-concat: Avoid assert-crashing.

[dovecot at dovecot.org]

details:   http://hg.dovecot.org/dovecot-2.0/rev/90fb346baeb2
changeset: 12321:90fb346baeb2
user:      Timo Sirainen <tss at iki.fi>
date:      Wed Oct 20 18:49:07 2010 +0100
description:
istream-concat: Avoid assert-crashing.

diffstat:

 src/lib/istream-concat.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (19 lines):

diff -r b884441a713f -r 90fb346baeb2 src/lib/istream-concat.c
--- a/src/lib/istream-concat.c	Wed Oct 20 17:51:07 2010 +0100
+++ b/src/lib/istream-concat.c	Wed Oct 20 18:49:07 2010 +0100
@@ -70,9 +70,12 @@
 	/* we already verified that the data size is less than the
 	   maximum buffer size */
 	cstream->istream.pos = 0;
-	if (!i_stream_get_buffer_space(&cstream->istream, data_size, &size))
-		i_unreached();
-	i_assert(size >= data_size);
+	if (data_size > 0) {
+		if (!i_stream_get_buffer_space(&cstream->istream,
+					       data_size, &size))
+			i_unreached();
+		i_assert(size >= data_size);
+	}
 
 	cstream->prev_stream_left = data_size;
 	memcpy(cstream->istream.w_buffer, data, data_size);