> > However, I do not like the idea of saying that HIGHLIGHT_SYNTAX has an
> > invalid value, and yet setting the value still does something (causes
> > "source-highlight") to be used. It seems more straightforward to make
> > it so that an invalid value is as if the variable were not set at all.
Agree!
> > + } elsif ($highlight_type eq 'source-highlight') {
> > $highlight_type = 'source-highlight';
We no longer need to set the "highlight_type" here once we already
ensure that it holds 'source-highlight' as value.
Also, do you prefer to amend my previous commit with this changes to
include the tests? Or do you like me to send a new patch?