From 30d0ddb20db36140b3ccf4fb820dcd95ea9322d4 Mon Sep 17 00:00:00 2001
From: vnxme <46669194+vnxme@users.noreply.github.com>
Date: Sun, 11 Aug 2024 22:54:27 +0300
Subject: [PATCH] Fix a regression in #6480: the context may have no replacer
 (e.g. in TestDefaultSNI)

---
 modules/caddytls/matchers.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/modules/caddytls/matchers.go b/modules/caddytls/matchers.go
index 83a464713819..f946223741b5 100644
--- a/modules/caddytls/matchers.go
+++ b/modules/caddytls/matchers.go
@@ -50,12 +50,13 @@ func (MatchServerName) CaddyModule() caddy.ModuleInfo {
 
 // Match matches hello based on SNI.
 func (m MatchServerName) Match(hello *tls.ClientHelloInfo) bool {
+	repl := caddy.NewReplacer()
 	// caddytls.TestServerNameMatcher calls this function without any context
-	var repl *caddy.Replacer
 	if ctx := hello.Context(); ctx != nil {
-		repl = ctx.Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
-	} else {
-		repl = caddy.NewReplacer()
+		// In some situations the existing context may have no replacer
+		if replAny := ctx.Value(caddy.ReplacerCtxKey); replAny != nil {
+			repl = replAny.(*caddy.Replacer)
+		}
 	}
 
 	for _, name := range m {