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
shaka-project · Jan 30, 2023 · c534602 · c534602
1 parent c6b4078
commit c534602
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diff --git a/lib/text/vtt_text_parser.js b/lib/text/vtt_text_parser.js
@@ -311,8 +311,8 @@ 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
@@ -1064,6 +1064,22 @@ 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