bug#27089: severe bug with XEmbedding

[René Kuligowski]

Dear people, please take a look into this:

just found somethind weird while being annoyed that I could not embed 
emacs-25.2-lucid into another window and played around with 
emacs-25.2-gtk2 (both compiled from the same tree):

– if you use the *decimal* pwinid as parameter to --parent-id and a GTK 
version of Emacs, you can embed Emacs into any X window which is serving.
– If you use the *hex* pwinid directly from a program’s output via an 
intermediary file or a pipe, emacs crashes or exits with an X error.
– If you use a non-GTK X version, emacs either exits with an X error 
(hex ID) or it does not work at all (emacs 25.2-lucid hangs in an 
infinite loop, doesn’t respond except to a SIGKILL and loads 35% onto a 
CPU).

Please fix whatever is broken or at least officially state the problem; 
this is not X embedding, but GTK specific, and should not be called 
„XEmbedding” while it is not.

Regards,
R. Kuligowski