[dvipdfmx] forward references

[Shunsaku Hirata]

Hi,

> I have tracked down the problem to what I would naively call the
> resolution of "forward references" in xdvipdfmx. "Naively", because I
> have no idea how that program works, and I'm not even sure whether to
> call the problem a feature or a bug. The issue is explained in detail in
> https://github.com/sasozivanovic/memoize/issues/1.

As you noted in the github issue above, the problem is that you are trying
to reference an object before it is defined. It is possible for dvipdfmx to
workaround this problem, however, the problem itself is improper use of
object reference and hence not a bug of dvipdfmx.

If this issue is simply a problem of "forward references" of objects, it could
be resolved relatively easily. However, in this example, a graphics object
("pgfshade1" for shading) is placed before it is defined. This makes it
difficult to resolve the issue.

> I would appreciate it if you could take the time to see if the second
> approach to the resolution of the issue (as proposed in the github
> issue) is feasible. And if it is, I would of course be very happy if the
> issue could be addressed.

I think it is feasible, but it may take some time to inspect the impact of
changing dvipdfmx behavior.

I will consider how this issue can be resolved.


Thanks,
Shunsaku Hirata