Wikimedia Bugzilla is closed!

When an apostrophe appears in a text for a button, everything after the
apostrophe is lost.

For example, mediawiki:savefile in Walloon is "Schaper l' fitchî" (note the
apostrophe).
That text is displayed in a button when uploading a file with warnings.

The html of the rendered page is as follow:

...  <input tabindex='2' type='submit' name='wpUpload' value='Schaper l' fitchî'
/> ...

Here you see what the problem is, the text in the value= field is enclosed in
single quotes, and the the single quote in the text itself isn't escaped.
As a result, the button only shows "Schaper l" instead of "Schaper l' fitchî".

All text that is to be displayed in the rendered page  that way should be
escaped for apostrophes.