JavaScript code is rendered while saving a new discussion title

[matteocontrini]

Bug Report

Current Behavior

When editing the title of a discussion, while the saving is in progress, the title of the discussion beneath the modal becomes some JavaScript code.

2021-02-20_23-19-10.mp4

Steps to Reproduce

1. Go to https://nightly.flarum.site/
2. Create a discussion
3. Rename the discussion title
4. Notice that while the new title is being saved, the title beneath the modal becomes some JavaScript code

Environment

• Flarum nightly

[Ralkage]

I can confirm this is also reproducible on https://beta.flarum.site which is on Beta 15 atm:

2021-02-25_17-22-33.mp4

[deebug]

I have a recording with a slight delay on when the issue occurs. Might be helpfull.

rename.mp4

[dsevillamartin]

I think this is because we're passing the Stream function instead of its value.

https://github.com/flarum/core/blob/0a6c5217c11e625aab5deec05bf6a6caf31bfa0d/js/src/forum/components/RenameDiscussionModal.js#L14

https://github.com/flarum/core/blob/0a6c5217c11e625aab5deec05bf6a6caf31bfa0d/js/src/forum/components/RenameDiscussionModal.js#L52-L60

Looks like the Mithril request automatically calls the function, but the Model value is temporarily set to the function and not its output.

The fix here, if I'm correct, would be to change const title = this.newTitle; to const title = this.newTitle();

[askvortsov1]

That fixes it for me locally. Could you open a PR?

[dsevillamartin]

@askvortsov1 Done :)