[Plplot-devel] Small API compatibility break.

[<jca...@in...>]

Hi,

While working on x20c.c, I noticed that plxormod() should return a=20
status, saying that the device is or is not capable of such=20
operation. The user code would then conditionaly execute code that=20
uses or not xor mode.
The change, to be usefull, would imply also minor changes in xwin.c=20
and tk.c, adding a device option has_xormod, but this is transparent=20
to the user (all is ready for commit).

This will break compatibility with previous releases of plplot. What=20
do you think? I think that plxormod() is not widely used, so there=20
should be no problems for most users.

Joao