Web UI does not allow empty wiki pages, but does not notify about that

[delvh]

Gitea Version

1.16.0+dev-339-gee73d8409

Operating System

Linux

Browser Version

Firefox 93

Can you reproduce the bug on the Gitea demo site?

Yes

Description

There seems to be a silent failure when attempting to publish a wiki page without content:
The save page button on the new page editor will simply act as if it was never pressed.
I think it would be better to notify the user that the content cannot be empty, just as the edit page editor does - yes, there is different behavior between the two.

Screenshots

No response

[delvh]

Since when do we have a theme/wiki label? In a quick search prior today it was not present…

[zeripath]

Since I added it for this one 🧙

[dvejmz]

I found a fix for this, will raise a PR shortly with more info.