From afeb3763dd1d08c4c15c4c4183fd5705da60dc4c Mon Sep 17 00:00:00 2001
From: BurtonQin <bobbqqin@gmail.com>
Date: Tue, 21 Apr 2020 07:15:04 -0400
Subject: [PATCH] cmd/go/internal/modfetch: add Unlock before return in
 checkModSum

---
 src/cmd/go/internal/modfetch/fetch.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/cmd/go/internal/modfetch/fetch.go b/src/cmd/go/internal/modfetch/fetch.go
index 61759c0e6b..fd7a5cef83 100644
--- a/src/cmd/go/internal/modfetch/fetch.go
+++ b/src/cmd/go/internal/modfetch/fetch.go
@@ -514,6 +514,7 @@ func checkModSum(mod module.Version, h string) error {
 	goSum.mu.Lock()
 	inited, err := initGoSum()
 	if err != nil {
+		goSum.mu.Unlock()
 		return err
 	}
 	done := inited && haveModSumLocked(mod, h)