Bug#325088: netpbm: pnmtopng -alpha <alphafile> <file> produces incorrect output

[Andreas Metzler]

On 2005-08-26 Nigel Williams <nigelw+debian at elder-gods.net> wrote:
> Package: netpbm
> Version: 2:10.0-8
> Severity: normal

> The following sequence of commands should result in an identical bitmap,
> but does not. It has a small vertical black bar in it.

> ---
> pngtopnm yellow_red_gradient.png > x.pnm
> pngtopnm -alpha yellow_red_gradient.png > y.pnm
> pnmtopng -alpha y.pnm x.pnm > z.png
> ---

> Interestingly, this problem did not occur when I had prelinked my
> libraries (debian package "prelink"), but does on both a clean
> (never prelinked) and un-prelinked machine.

> source image is here, uuencoded:
[...]

Hello Nigel,

Debian's netbpm packages have switched to the netpbm codebase and afaict
the abovementionend breakage is not reproducible anymore, z.png and
yellow_red_gradient.png look identical.

cu Andreas