commit 73392c2c7cc2e74759480a37e345366dfa265926
from: David du Colombier <0intro@gmail.com>
via: Russ Cox <rsc@swtch.com>
date: Mon Dec 12 21:44:50 2011 UTC

libventi: fix segfault in vtreadpacket when not connected

This problem happens especially in fossil/view when vtread
can be called even if not connected to venti.

The old libventi handle this case properly in the function vtRPC, which is called by vtReadPacket (client.c).

R=rsc
CC=plan9port.codebot
http://codereview.appspot.com/5484044

commit - ca81de0ae174e737cf3594787fa885e51d6e9d1d
commit + 73392c2c7cc2e74759480a37e345366dfa265926
blob - 9f200f48c2e8f60061c902534fb084c4cc60fbf4
blob + f76fd343311a1425179904239088739960a0289c
--- src/libventi/client.c
+++ src/libventi/client.c
@@ -65,6 +65,11 @@ vtreadpacket(VtConn *z, uchar score[VtScoreSize], uint
 	if(memcmp(score, vtzeroscore, VtScoreSize) == 0)
 		return packetalloc();
 
+	if(z == nil){
+		werrstr("not connected");
+		return nil;
+	}
+
 	if(z->version[1] == '2' && n >= (1<<16)) {
 		werrstr("read count too large for protocol");
 		return nil;