Fixed WebUI crash when a status opened in the media modal is deleted

[kaias1jp]

Fixed a problem that a compatibility error occurs when the status is deleted while the status image etc. is selected and displayed.

[ClearlyClaire]

Thank you for the contribution! I took the liberty of changing the PR title to reflect that it's not a compatibility error but just a crash.

Your change seem to fix the crash itself, but it would result in the pop-out player still being displayed, although without the status bar. A better approach would probably be to close the pop-out player as soon as the status is deleted.

This could be handled by changing app/javascript/mastodon/reducers/picture_in_picture.js to process status deletion the same way as PICTURE_IN_PICTURE_REMOVE when the deleted status id is the currently-displayed one. Statuses are deleted through a TIMELINE_DELETE action (see app/javascript/mastodon/reducers/statuses.js for example).

[kaias1jp]

Thank you. You're right. I will consider how to close the pop-out player, but should this PR be closed once? Since this was my first PR, I don't know what to do in such a case. If you do not mind, please teach me.

[ClearlyClaire]

You can push additional commits in the PR. I'd start by reverting the latest commit (git revert HEAD) and continue working as before.

This will result in a slightly noisy commit history, but that isn't really an issue. If you still want to clean that commit history later on, you can use git rebase -i, but that is completely optional.

[kaias1jp]

I reconfirmed where the crash occurred.
What I found was that the WebUI crashed when the status was deleted when the image was displayed modally.
So I want to change the title to "Fixed WebUI crashing when status is deleted when displaying images modally".
As an additional fix, I would like to close the image only if the modally displayed image has a deleted status.
The pop-out player does not crash, but I think it is necessary to close the player by deleting the status. I'm wondering whether to include this in this PR or put it out as another PR.

[ClearlyClaire]

Ah yes, there is indeed a similar crash in the media modal. I'd say it's a similar issue but not exactly the same. I don't have a preference with regards to fixing both issues in the same PR or different ones, do what's easiest for you.

[ClearlyClaire]

Looks good to me, thanks!