Incorrect subtitle rendering after jumping when playing with an external PGS subtitle

[dyphire]

Important Information

Provide following Information:

• mpv version: git master
• Windows Version: Win11 23H2
• Source of the mpv binary: https://github.com/zhongfly/mpv-winbuild
• If known which version of mpv introduced the problem

Reproduction steps

Try using --no-config to play a video with external PGS subtitles and perform a seek or jump operation after displaying the subtitle content.

Expected behavior

Normal playback after the seek or jump, subtitle events are rendered normally.

Actual behavior

The subtitle content of PGS subtitles displayed before the seek or jump will still be displayed after the seek or jump and will continue until the correct subtitle content appears after the seek or jump.

https://github.com/mpv-player/mpv/assets/61936050/ac55f8bf-d90c-4823-9bd8-2c065c105ef0

This issue only appears on external PGS subtitles.

Log file

mpv.log

Sample files

Considering that external PGS subtitles are not common, I upload a sample subtitle, extracted from an mkv file. This is not a good example file, and it has dense subtitle events making the issue less obvious.

[Beatrice-Raws] Evangelion 3.333 You Can (Not) Redo [BDRip 3840x1632 HEVC TrueHD]_rev.Jpn.sup.zip

[cubicibo]

The sample in #12760 exacerbates the issue and makes it easier for debugging.