fix(HLS): Fix subtitle timing when no discontinuity but there is X-TIMESTAMP-MAP

[avelad]

Fixes #7673

[markuswolters]

Thanks @avelad for the quick fix. I'm wondering if that's another bug, at least with the 4.12.1/4.11.13 versions: When subtitles are turned on and I do a fast skip while video is buffering (e.g. video is playing, then I skip +30seconds, video goes into buffering mode, then - while still in buffering - I do another skip +30s), 50% chances are that subtitles are not being displayed anymore until stream gets reloaded completly. When I delay the next skip until buffering has finished, everything is fine. Does this hint you to something?

I do see these debug outputs during skips while video buffering:

shaka-player.ui.debug.js:151 (audio:12) clear: currently updating
shaka-player.ui.debug.js:151 (audio:12) Aborting operation due to seek
shaka-player.ui.debug.js:151 (video:26) clear: currently updating
shaka-player.ui.debug.js:151 (video:26) Aborting operation due to seek
shaka-player.ui.debug.js:151 (text:30) clear: currently updating
shaka-player.ui.debug.js:151 (text:30) Aborting operation due to seek

[avelad]

I can't reproduce that in the main branch...

[markuswolters]

Thanks, I will verify with the main branch.