[release-branch.go1.16] net/http/httptest: wait for user ConnState hooks
Ensure that user ConnState callbacks have completed before returning
from (*httptest.Server).Close.
Fixes: #49851
Updates: #37510
Updates: #37505
Updates: #45237
Change-Id: I8fe7baa089fbe4f3836bf6ae9767c7b1270d1331
Reviewed-on: https://go-review.googlesource.com/c/go/+/304829
Trust: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
(cherry picked from commit 5cec8b85e5dc75ef21b62efb6bd93f9007385e34)
Reviewed-on: https://go-review.googlesource.com/c/go/+/367516
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/src/net/http/httptest/server.go b/src/net/http/httptest/server.go
index 65165d9..a02a6d6 100644
--- a/src/net/http/httptest/server.go
+++ b/src/net/http/httptest/server.go
@@ -316,6 +316,13 @@
s.Config.ConnState = func(c net.Conn, cs http.ConnState) {
s.mu.Lock()
defer s.mu.Unlock()
+
+ // Keep Close from returning until the user's ConnState hook
+ // (if any) finishes. Without this, the call to forgetConn
+ // below might send the count to 0 before we run the hook.
+ s.wg.Add(1)
+ defer s.wg.Done()
+
switch cs {
case http.StateNew:
s.wg.Add(1)
