Successive layer effects should use a higher bit-depth as intermediary format
Looking at #12359 (closed), it looks like between 2 successive effects on a same layer, we are going back to source format. Unfortunately when this format is very low bit-depth, it may mean a lot of color loss.
Reproduction
Is the bug reproducible? Always
Reproduction steps:
- Open dark16.xcf (looks all black)
- Increase exposure by +8 stops, resulting in normal image
- Change encoding to 8-bit linear light, resulting in very black/posterized image
Even though the 8-bit linear sRGB space has a huge precision loss, 2 filters canceling each others could still render very similarly to the input if we use high-bit depth format as intermediary format.