> > (while (= ";" (last (last L)))
> > (char) # Skip TAB
> > (conc L (trim (split (line) " "))) )
> which only folds the next line of a multiline header if the existing
> line ends with ";" and then chomps a single leading char, yet as far
> as I understand it, RFC822 supports [A] folding based on (single or
> multiple) leading TABs or spaces, [B] even if the preceding line
> doesn't end with a ";" :
> gmail/google-apps users I noticed they often have a mix of
> multiline-header-continuations with leading SPACEs (multiple) and some
> with leading TABs, and several are just folded on space without the
> trailing ";" so it seems this isn't a theoretical edge-case...
Indeed! This looks like a possible source of the problems.
> Obviously chomping only one of multiple leading spaces/tabs probably
> doesn't matter (other than for readability of mail-source), but only
> matching the fold on a trailing ";" certainly does. I suspect that is
I'm rather confused now about what would be the right way to handle this.