[dvipdfmx] pdf:bxgstate fails if other packages add opacity too

[Ulrike Fischer]

I try the new \special{pdf:bxgstate ...} ... \special{pdf:exgstate}
(using the binary from w32tex.org)

When used alone in a document it works fine, but if use together with
a package which sets ExtGState too, e.g. tikz it fails to correctly
reset a transparency after a page break


\RequirePackage{l3pdf}
\ExplSyntaxOn
\pdf_uncompress:
\ExplSyntaxOff
\documentclass{article}
\usepackage{tikz}
\begin{document}
blblbllb
\tikz[opacity=0.3]\fill[red](0,0)rectangle(1,1);
\special{pdf:bxgstate << /CA 0.2 /ca 0.2 >>}
   Transparent\newpage text. %second page is black again
\special{pdf:exgstate}%
\end{document}


Looking in the pdf one can see that the ExtGState entries have been
correctly merge, but the numbering of the dvipdfmx entries are wrong:

The dictionary shows 0 and 2:


<</pgf at CA0.3<</CA .3>>
  /pgf at ca0.3<</ca .3>>
  /DPX_GS0<</CA .2/ca .2>>
  /DPX_GS2<</CA 1/ca 1>>
>>


and the stream of the first pages uses the 0 entry /DPX_GS0 gs, but on the second
page /DPX_GS1 gs is used.


With tikz only one ExtGState object is used and referenced by every
page, without tikz every page has its own ExtGState setting.


Ulrike Fischer