From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 11 Sep 2009 18:21:37 +0000 (+0000)
Subject: Treat a negative number of bytes to read as the kernel saying "I don't know."
X-Git-Tag: release-2.0.3-alpha~112
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3b461a6d03927220eae00e232d26053c71afd60f;p=libevent

Treat a negative number of bytes to read as the kernel saying "I don't know."

svn:r1426
---

diff --git a/ChangeLog b/ChangeLog
index cb4900af..fa69e4a4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,7 +17,7 @@ Changes in 2.0.3-alpha:
  o Support sendfile on Solaris: patch from Caitlin Mercer.
  o New functions to explicitly reference a socket used by an evhttp object. Patches from David Reiss.
  o When we send a BEV_EVENT_CONNECTED to indicate connected status, we no longer invoke the write callback as well unless we actually wrote data too.
-
+ o If the kernel tells us that there are a negative number of bytes to read from a socket, do not believe it.  Fixes bug 2841177; found by Alexander Pronchenkov.
 
 Changes in 2.0.2-alpha:
  o Add a new flag to bufferevents to make all callbacks automatically deferred.
diff --git a/buffer.c b/buffer.c
index 0cd6df50..370823e2 100644
--- a/buffer.c
+++ b/buffer.c
@@ -1607,9 +1607,9 @@ evbuffer_read(struct evbuffer *buf, evutil_socket_t fd, int howmuch)
 
 #if defined(FIONREAD)
 #ifdef WIN32
-	if (ioctlsocket(fd, FIONREAD, &lng) == -1 || (n=lng) == 0) {
+	if (ioctlsocket(fd, FIONREAD, &lng) == -1 || (n=lng) <= 0) {
 #else
-	if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
+	if (ioctl(fd, FIONREAD, &n) == -1 || n <= 0) {
 #endif
 		n = EVBUFFER_MAX_READ;
 	} else if (n > EVBUFFER_MAX_READ && n > howmuch) {