wrong spot colors after \colorlet #11
Description
pgf assigns some colors using the implicit color . and the pseudo model named. Both doesn't work with colorspace:
\documentclass{article}
\usepackage{colorspace}
\definespotcolor{myblue}{HKS 44 K}[cmyk]{1,0.5,0,0}
\begin{document}
\colorlet{.}{myblue}
\colorlet{implicittest}{.}
\expandafter\show\csname\string\color@implicittest\endcsname
\color{red} aaa
\expandafter\show\csname\string\color@.\endcsname
\colorlet[named]{namedtest}{myblue}
\expandafter\show\csname\string\color@namedtest\endcsname
\end{document}
This gives the two invalid colors (and so breaks the pdf):
> \\color@implicittest=macro:
->\xcolor@ {}{0 cs 0 CS 1 sc 1 SC}{&spot}{1}.
> \\color@namedtest=macro:
->\xcolor@ {}{0 cs 0 CS 1 sc 1 SC}{&spot}{1}.
I would suggest to add similar to issue #10 a light weight test to \spc@getref if it actually got a correct spot color.
This doesn't resolve everything. If there is a second spotcolor and \colorlet[named]{namedtest}{myred} is used, then it gets the wrong color. But at least there is a warning and the pdf is not broken.
\documentclass{article}
\usepackage{colorspace}
\definespotcolor{myblue}{HKS 44 K}[cmyk]{1,0.5,0,0}
\makeatletter
\ExplSyntaxOn
\def\spc@getref#1~#2\@@
{
\tl_if_head_eq_charcode:nNTF {#1}/
{\gdef\spc@ir{#1}}
{
\PackageWarning{colorspace}{#1~is~not~a~spot~color!\MessageBreak
Trying~implicit~color~.}{}
\spc@getir{\string\color@.}
\tl_if_head_eq_charcode:fNF {\spc@ir}/
{
\PackageError{colorspace}{#1~is~not~a~spot~color!}{}
}
}
}
\ExplSyntaxOff\makeatother
\begin{document}
\colorlet{.}{myblue}
\colorlet{implicittest}{.}
\expandafter\show\csname\string\color@implicittest\endcsname
\color{red} aaa
\expandafter\show\csname\string\color@.\endcsname
\colorlet[named]{namedtest}{myblue}
\expandafter\show\csname\string\color@namedtest\endcsname
\end{document}