From: Marcus Sundberg <marcus@marcussundberg.com>
Date: Sat, 26 Mar 2016 19:11:43 +0000 (+0100)
Subject: evbuffer_add: Use last_with_datap if set, not last.
X-Git-Tag: release-2.1.6-beta~42^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a8769ef12d7e223e33fc47bed03fba2bfa2f3536;p=libevent

evbuffer_add: Use last_with_datap if set, not last.

evbuffer_add() would always put data in the last chain, even if there
was available space in a previous chain, and in doing so it also
failed to update last_with_datap, causing subsequent calls to other
functions that do look at last_with_datap to add data in the middle
of the evbuffer instead of at the end.

Fixes the evbuffer_add() part of issue #335, and the evbuffer/add2 and
evbuffer/add3 tests, and also prevents wasting space available in the
chain pointed to by last_with_datap.
---

diff --git a/buffer.c b/buffer.c
index 7cca0e8a..f378b731 100644
--- a/buffer.c
+++ b/buffer.c
@@ -1732,7 +1732,11 @@ evbuffer_add(struct evbuffer *buf, const void *data_in, size_t datlen)
 		goto done;
 	}
 
-	chain = buf->last;
+	if (*buf->last_with_datap == NULL) {
+		chain = buf->last;
+	} else {
+		chain = *buf->last_with_datap;
+	}
 
 	/* If there are no chains allocated for this buffer, allocate one
 	 * big enough to hold all the data. */