sync: simplify TestOncePanic

Follow-up to CL 137350043.

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/141620043

diff --git a/src/sync/once_test.go b/src/sync/once_test.go
index 10beefde35d512f5aee39493ec84cbfcebf815f2..1eec8d18ea52e93aec5c6d115d30227ad3b383fb 100644 (file)
--- a/src/sync/once_test.go
+++ b/src/sync/once_test.go
@@ -40,26 +40,20 @@ func TestOnce(t *testing.T) {
 }
 
 func TestOncePanic(t *testing.T) {
-       once := new(Once)
-       for i := 0; i < 2; i++ {
-               func() {
-                       defer func() {
-                               r := recover()
-                               if r == nil && i == 0 {
-                                       t.Fatalf("Once.Do() has not panic'ed on first iteration")
-                               }
-                               if r != nil && i == 1 {
-                                       t.Fatalf("Once.Do() has panic'ed on second iteration")
-                               }
-                       }()
-                       once.Do(func() {
-                               panic("failed")
-                       })
+       var once Once
+       func() {
+               defer func() {
+                       if r := recover(); r == nil {
+                               t.Fatalf("Once.Do did not panic")
+                       }
                }()
-       }
-       once.Do(func() {})
+               once.Do(func() {
+                       panic("failed")
+               })
+       }()
+
        once.Do(func() {
-               t.Fatalf("Once called twice")
+               t.Fatalf("Once.Do called twice")
        })
 }