#121 Undeclared conditional breaks \pgfmath@@declarefunction

[Eric Domenjoud]

The following code breaks \pgfmath@@declarefunction.

\pgfmathdeclarefunction{func}{1}{%
  \checkarg{#1}
  \ifchecked
    \def\pgfmathresult{1}%
  \else
    \def\pgfmathresult{0}%
  \fi
}

\newif\ifchecked

\def\checkarg#1{%
  \ifdim#1pt>0pt
    \checkedtrue
  \else
    \checkedfalse
  \fi
}

TeX reports

! Too many }'s.
\pgfmath@@declarefunction ...def #1{#2}\def #2{#4}
\or \def #1##1{\pgfmathpar...

The reason is that when func is declared, \ifchecked has not yet been defined. Tex does not see it as a conditional and interprets the \fi statement in the body of func as closing the \ifcase conditional in \pgfmath@@declarefunction.

The solution is to defer the definition of the function after \ifcase ... \fi.

[Eric Domenjoud]

Sorry, this should be a bug report. It ended up in the wrong category and sourceforge does not allow me to move or modify the ticket.

[Henri Menke]

Fixed in https://sourceforge.net/p/pgf/git/ci/fd9258d8273d46387438ae9ad442e8d24dcd0e71/

The MWE could have been much shorter:

\input pgf.tex
\pgfmathdeclarefunction{func}{1}{\ifwhatever\fi}
\bye