In query design mode, when entering into the LIMIT box (rightmost element of the default toolbar) any "invalid" string, such as for example "my tailor is rich", the new value is silently discarded instead of displaying a helpful error message.
IMHO that error message should have two buttons, one button that discards the new value and goes back to the old one, and one button that gives the user the opportunity to edit the string without losing what he/she has typed.
The "Font Size" box in Writer does yet something else: it silently discards non-digits (such as letters and spaces).
For the sake of consistency, maybe it would be better to do the same for the LIMIT box in Query Design, rather than my personal idea/preference of error message.
Yes, FontSizeBox inherite this behaviour from NumerciBox, from which LimitBox is also derived, so it works the same, at least from this point of view.
Indeed, I now see that the new value is completely discarded only if the newly entered string has no digit at all. If I enter a mix of letters and digits, then indeed the letters are dropped and the digits kept. I had not noticed that when I entered this bug.
This is indeed the same behaviour as other similar boxes in LibreOffice, and reasonable. Closing this bug as invalid.