runtime: better error for send/recv on nil channel

R=ken2
CC=golang-dev
https://golang.org/cl/1835041

diff --git a/src/pkg/runtime/chan.c b/src/pkg/runtime/chan.c
index 08cd75a6e53971e111edff93910d3c20ef7d33d7..9e88e824a4b584ce902565b5a9e9c00d66314751 100644 (file)
--- a/src/pkg/runtime/chan.c
+++ b/src/pkg/runtime/chan.c
@@ -182,6 +182,9 @@ chansend(Hchan *c, byte *ep, bool *pres)
        SudoG *sg;
        G* gp;
 
+       if(c == nil)
+               panicstring("send to nil channel");
+
        if(gcwaiting)
                gosched();
 
@@ -286,6 +289,9 @@ chanrecv(Hchan* c, byte *ep, bool* pres)
        SudoG *sg;
        G *gp;
 
+       if(c == nil)
+               panicstring("receive from nil channel");
+
        if(gcwaiting)
                gosched();