load_lut took any source containing "LUT_" for inline .cube text, so a
path like /luts/LUT_Rec709.cube was parsed as text, failed, and the
effect passed the image through. A .cube can only parse with a size
header and data rows on separate lines, so a newline (after trimming,
as the path already is) is what tells text from a path.
arnav-hiwarkar
6540c9ab44