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

[Shunsaku Hirata]

I made a patch for this issue and it should be included soon.

> both tikz and also our pdfresources project uses one global indirect object
> for resources like ExtGState and ColorSpace used by all pages.
>
> The first is used a lot, and the second hopefully will be used in the
> future. So probably it isn't really needed that dvipdfmx tries at
> first to create individual entries per page and do complicated merges,
> at the end most documents will have a global object. You could provide
> an @extgstate object, and everyone could simply use it (additionally,
> to be on the safe side you could merge with other objects containing
> extgstate entries.) And similar for ColorSpace.

Probably an extended syntax like @resources:extgstate would be
better to avoid object name collision as much as possible.

I will consider extending predefined names along with other
extensions related to multiple (color) stacks.


Thanks,
Shunsaku Hirata