0.90 : Converting image from PNG to JPEG has weird result

[reportma]

XnView: Version 0.90 64bits (Mar 4 2018)
OS: Windows 10 64bit

Hi, I want to convert a PNG image to JPEG but the image result is weird.

Source:
XnView:

I tried converting using other programs, there's no problem.
Windows Paint:
Gimp:

Gimp has the best result, can you replicate Gimp's conversion method?

[xnview]

See issue for current status and some details.

[deus-ex]

Hi Pierre,

I just tested this feature with the current release v0.93 64-bit on Windows 10. I confirm that the example PNG image posted by the the OP gets saved correctly to the JPG format, without applying the thick black border that is masked by the alpha channel in the original PNG image.