From da84a2c86b7d7e6968472ce9d2bbe09e0608dbef Mon Sep 17 00:00:00 2001
From: Joey Parrish <joeyparrish@users.noreply.github.com>
Date: Thu, 19 Jan 2023 11:53:22 -0800
Subject: [PATCH] fix: Fix WebVTT parser failure on REGION blocks (#4915)

We do not yet support VTT region settings, but we should still not fail
when a region block appears in a VTT file.

Related to work on PR #4767
---
 lib/text/vtt_text_parser.js       |  4 ++--
 test/text/vtt_text_parser_unit.js | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/lib/text/vtt_text_parser.js b/lib/text/vtt_text_parser.js
index 562863ec77..349e12c6f5 100644
--- a/lib/text/vtt_text_parser.js
+++ b/lib/text/vtt_text_parser.js
@@ -337,8 +337,8 @@ shaka.text.VttTextParser = class {
       return null;
     }
 
-    // Skip style blocks.
-    if (text[0] == 'STYLE') {
+    // Skip style and region blocks.
+    if (text[0] == 'STYLE' || text[0] == 'REGION') {
       return null;
     }
 
diff --git a/test/text/vtt_text_parser_unit.js b/test/text/vtt_text_parser_unit.js
index a33025b981..d4c4d4907e 100644
--- a/test/text/vtt_text_parser_unit.js
+++ b/test/text/vtt_text_parser_unit.js
@@ -1181,6 +1181,22 @@ describe('VttTextParser', () => {
         {periodStart: 0, segmentStart: 0, segmentEnd: 0, vttOffset: 0});
   });
 
+  it('does not fail on REGION blocks', () => {
+    verifyHelper(
+        [
+          {
+            startTime: 10, endTime: 20,
+            payload: 'test',
+          },
+        ],
+        'WEBVTT\n\n' +
+        'REGION\n' +
+        'id:1\n\n' +
+        '00:00:10.000 --> 00:00:20.000\n' +
+        'test\n\n',
+        {periodStart: 0, segmentStart: 0, segmentEnd: 0, vttOffset: 0});
+  });
+
   /**
    * @param {!Array} cues
    * @param {string} text