From 75032ad8cfac4aefbacd17b47346ac8c1b5ff33f Mon Sep 17 00:00:00 2001
From: Mark Rushakoff <mark.rushakoff@gmail.com>
Date: Thu, 8 Oct 2020 02:12:43 +0000
Subject: [PATCH] cmd/go: break after terminal loop condition
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

After the first time needCostly is set to true, there is no need to
continue checking the remaining args.

Change-Id: I07171ce50d20e2a917117a0f84c442fe978cb274
GitHub-Last-Rev: 6d0c19341b7a85d507c3ec4967bab5f83b0fad8d
GitHub-Pull-Request: golang/go#41859
Reviewed-on: https://go-review.googlesource.com/c/go/+/260638
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Go Bot <gobot@golang.org>
---
 src/cmd/go/internal/envcmd/env.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index b5a48558fa..557e418921 100644
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -217,6 +217,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 		needCostly = true
 	} else {
 		needCostly = false
+	checkCostly:
 		for _, arg := range args {
 			switch argKey(arg) {
 			case "CGO_CFLAGS",
@@ -227,6 +228,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 				"PKG_CONFIG",
 				"GOGCCFLAGS":
 				needCostly = true
+				break checkCostly
 			}
 		}
 	}
-- 
2.48.1