headers: Support repeated WriteHeader if 1xx (fix #5074)

caddyserver · Sep 23, 2022 · 7041970 · 7041970
1 parent eead00f
commit 7041970
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/modules/caddyhttp/headers/headers.go b/modules/caddyhttp/headers/headers.go
@@ -332,7 +332,10 @@ func (rww *responseWriterWrapper) WriteHeader(status int) {
 	if rww.wroteHeader {
 		return
 	}
-	rww.wroteHeader = true
+	// 1xx responses aren't final; just informational
+	if status < 100 || status > 199 {
+		rww.wroteHeader = true
+	}
 	if rww.require == nil || rww.require.Match(status, rww.ResponseWriterWrapper.Header()) {
 		if rww.headerOps != nil {
 			rww.headerOps.ApplyTo(rww.ResponseWriterWrapper.Header(), rww.replacer)