Using RMagick matte_floodfill randomly loses transparency on Gentoo

[dziemid]

Hello,

Not sure if it's RMagick or ImageMagick problem..

I have an image with transparent background.

When running following operations:

Code: Select all

image = Magick::Image.read('input.png').first
img = image.channel(Magick::OpacityChannel)
img.matte_floodfill(0, 0).write('result.png')

On OSX I am getting an image with transparent background. When run on Gentoo system, I am sometimes (50% of times) getting image with white background. Expected behaviour is that it should stay transparent.

More details here:

https://github.com/redbubble/matte_floodfill_problem
https://github.com/gemhome/rmagick/issues/187

Thank you for help
Greg