From f664d0e90421cf7b6257ce2f0ad197a7d76ff7a0 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Mon, 20 Jul 2009 13:29:56 -0700
Subject: [PATCH] explain selectsend problem

R=ken
OCL=31865
CL=31867
---
 src/cmd/gc/walk.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 65c4f7efd6..be3f0b9cb7 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -606,7 +606,10 @@ reswitch:
 			ll = ascompatte(n->op, getinarg(t), n->list, 0, init);
 			n->list = reorder1(ll);
 			if(isselect(n)) {
-				// clear output bool - special prob with selectsend
+				// special prob with selectsend and selectrecv:
+				// if chan is nil, they don't know big the channel
+				// element is and therefore don't know how to find
+				// the output bool, so we clear it before the call.
 				Node *b;
 				b = nodbool(0);
 				lr = ascompatte(n->op, getoutarg(t), list1(b), 0, init);
-- 
2.48.1