Support pattern objects with dvipdfmx

[doraTeX]

pgfsys-dvipdfmx.def seems not to support patterns library fully. Patterns are sometimes lost with the following error:

dvipdfmx:warning: Object @pgfpatternobject3 used, but not defined. Replaced by null.

Test code

%#!latex + dvipdfmx
\documentclass[dvipdfmx]{article}
\usepackage{tikz}
\usetikzlibrary{patterns}

\def\test{\tikz\filldraw[pattern=north east lines] (0,0) ellipse (2 and 1);}

\begin{document}
%%% Uncomment only one of the following choices.
%[1] \test %%% works correctly
[2] \setbox0\hbox{\test}\test %%% FAILS: patterns are lost
%[3] $\mathchoice{\test}{\test}{}{}$ %%% FAILS: patterns are lost
%[4] \test\setbox0\hbox{\test}\test %%% works correctly
%[5] \test$\mathchoice{\test}{\test}{}{}$ %%% works correctly
\end{document}

Result

When you uncomment [2] or [3] and compile it with LaTeX (DVI mode) + dvipdfmx, you will get an unfilled ellipse like this:

Solution

This problem does not occur when compiled with XeTeX (xdvipdfmx). So I tried replacing the definition of \pgfsys@dvipdfmx@patternobj in pgfsys-dvipdfmx.def with the one in pgfsys-xetex.def. This workaround seems to work well.