From e24143a1962c16763cb73f4e41b30117bcf0d80c Mon Sep 17 00:00:00 2001
From: Simon Zolin <s.zolin@adguard.com>
Date: Fri, 24 Apr 2020 15:50:57 +0300
Subject: [PATCH] - Web: flush the bufferred response data before performing
 global operations

---
 home/control_install.go | 7 +++++--
 home/control_update.go  | 4 +++-
 home/tls.go             | 5 ++++-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/home/control_install.go b/home/control_install.go
index 4a39983f..864ad96b 100644
--- a/home/control_install.go
+++ b/home/control_install.go
@@ -351,6 +351,11 @@ func (web *Web) handleInstallConfigure(w http.ResponseWriter, r *http.Request) {
 
 	registerControlHandlers()
 
+	returnOK(w)
+	if f, ok := w.(http.Flusher); ok {
+		f.Flush()
+	}
+
 	// this needs to be done in a goroutine because Shutdown() is a blocking call, and it will block
 	// until all requests are finished, and _we_ are inside a request right now, so it will block indefinitely
 	if restartHTTP {
@@ -358,8 +363,6 @@ func (web *Web) handleInstallConfigure(w http.ResponseWriter, r *http.Request) {
 			_ = Context.web.httpServer.Shutdown(context.TODO())
 		}()
 	}
-
-	returnOK(w)
 }
 
 func (web *Web) registerInstallHandlers() {
diff --git a/home/control_update.go b/home/control_update.go
index b0080e44..6115fac1 100644
--- a/home/control_update.go
+++ b/home/control_update.go
@@ -548,7 +548,9 @@ func handleUpdate(w http.ResponseWriter, r *http.Request) {
 	}
 
 	returnOK(w)
+	if f, ok := w.(http.Flusher); ok {
+		f.Flush()
+	}
 
-	time.Sleep(time.Second) // wait (hopefully) until response is sent (not sure whether it's really necessary)
 	go finishUpdate(u)
 }
diff --git a/home/tls.go b/home/tls.go
index 1e6267fe..5977f859 100644
--- a/home/tls.go
+++ b/home/tls.go
@@ -279,11 +279,14 @@ func (t *TLSMod) handleTLSConfigure(w http.ResponseWriter, r *http.Request) {
 		tlsConfigStatus:   t.status,
 	}
 	marshalTLS(w, data2)
+	if f, ok := w.(http.Flusher); ok {
+		f.Flush()
+	}
+
 	// this needs to be done in a goroutine because Shutdown() is a blocking call, and it will block
 	// until all requests are finished, and _we_ are inside a request right now, so it will block indefinitely
 	if restartHTTPS {
 		go func() {
-			time.Sleep(time.Second) // TODO: could not find a way to reliably know that data was fully sent to client by https server, so we wait a bit to let response through before closing the server
 			Context.web.TLSConfigChanged(data)
 		}()
 	}