\iftikz@mode@shade%
\pgfsyssoftpath@getcurrentpath\tikz@temppath
\pgfprocessround{\tikz@temppath}{\tikz@temppath}% change the path
\pgfsyssoftpath@setcurrentpath\tikz@temppath%
\pgfshadepath{\tikz@shading}{\tikz@shade@angle}%
\tikz@mode@shadefalse% no more shading...
\fi%