1.98: When rotating a png, background is always transparent

[Zverik]

0. Open a .png file
1. Open «Rotate custom» dialog
2. Enter non-zero value for an angle
3. Background of a picture is transparent. You cannot change this behaviour. It does not matter what color is selected as a background color.

Could you please add "transparency" checkbox and allow creating non-transparent images?
Luckily, "Remove alpha channel" works after that.

[xnview]

your png file has an alpha before?