Remove padding between interleaved PCX palette data by radarhere · Pull Request #9005 · python-pillow/Pillow

Resolves #8952

#535 added code to remove padding between bands.

for (i = 1; i < bands; i++) { // note -- skipping first band
memmove(
&state->buffer[i * state->xsize],
&state->buffer[i * stride],
state->xsize
);
}

However, that didn't consider that there might be padding between lines for interleaved data, like the P;4L image from the issue.

I've created the test image using Pillow and manual hexediting.