Bug#723573: xterm occasionally forgets BackSpace translation

[Zefram <zefram@fysh.org>]

retitle 723573 usual translations not applied when focus is on scrollbar
thanks

I've managed to reliably reproduce the problem.  When the mouse pointer
is located on the xterm's scrollbar, showing the up-and-down-arrow mouse
cursor, none of the translations in the "XTerm.vt100.translations"
resource get applied.  This doesn't only affect backspace, it also
affects some scrolling keys that I've set up in the same resource.
The translations are applied normally when the mouse pointer is in the
text part of the xterm, showing the I-beam mouse cursor, and when the
mouse pointer is on the window frame or titlebar, showing a mouse cursor
determined by the window manager.  Toggling the backspace option fixed
the problem merely by virtue of moving the mouse off the scrollbar.

The man page contains an oblique note about applying different
translations in the scrollbar context.  (It talks about changing mouse
button behaviour, not keys.)  It shows a resource name pattern of
"*VT100.scrollbar.translations".  Based on that, I've tried setting
a resource under the name "XTerm.vt100.scrollbar.translations", and
it turns out that the scrollbar context obeys translations that are
placed there.  As a permanent change, I've changed my resource settings
to specify the translations under a key of "XTerm.vt100*translations"
instead of "XTerm.vt100.translations".  Empirically this fixes the issue:
the translations now apply when focus is on the scrollbar as well as in
the other focus states.

So it may possibly be a bug that, in the absence of an overriding
XTerm.vt100.scrollbar.translations, XTerm.vt100.translations isn't applied
when focus is on the scrollbar.  Don't know whether that's intentional.
But it is certainly a bug that the names by which translation resources
are looked up are inadequately documented.  The man page describes
"translations" only as a resource for the "vt100" widget, not for the
"scrollbar" widget (except for the implication of the example in a
different section of the doc), and has no mention of translations being
applied differently depending on focus.

-zefram