true color refused if color-space-id is present
echo -e '\e[48:2:12345:100:200:250mfoobar'
This used to select a truecolor background in 0.52, but is ignored in 0.54 if a nonempty color-space-id is present. (Same with 38 and 58, obviously.)
Was this an intentional change, or an accidental breakage at the parser rewrite?
(Found on @textshell's page.)