Undesired addition of alpha channel

[AndreasW]

Using XnView MP 1.5.2 on iMac with Intel processor.

When you download this HEIC file, open it in XnView MP, and save it in PNG format, the PNG file will have an alpha channel. The original HEIC file had no alpha channel.

This is bad. I don't want this useless alpha channel.

(Note: On the Mac, in order to check whether an image has an alpha channel, you can select the file in the Finder and press command+I. The presence of an alpha channel will be shown in the info dialog; see screenshot below.)
 

[xnview]

Thanks to your detailed description I can reproduce the problem.

[xnview]

This problem is supposed to be fixed in XnView MP 1.5.3. Please check and confirm the bug fix here.

[AndreasW]

I've tested it. The problem is fixed. Thank you very much!