From b549b6036c4baa2b987f4c0276cc2b0edf623dc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Velad=20Galv=C3=A1n?= <ladvan91@hotmail.com>
Date: Thu, 8 Jun 2023 20:29:16 +0200
Subject: [PATCH] fix(HLS): Avoid variable substitution if no variables (#5269)

With this change, we improve performance on very large playlists.
---
 lib/hls/hls_parser.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
index f27aed2b0e..1c5c1384e9 100644
--- a/lib/hls/hls_parser.js
+++ b/lib/hls/hls_parser.js
@@ -2451,6 +2451,9 @@ shaka.hls.HlsParser = class {
    * @private
    */
   variableSubstitution_(uri, variables) {
+    if (!variables.size) {
+      return uri;
+    }
     let newUri = String(uri).replace(/%7B/g, '{').replace(/%7D/g, '}');
 
     const uriVariables = newUri.match(/{\$\w*}/g);