K 10
svn:author
V 3
cmt
K 8
svn:date
V 27
2019-10-28T14:42:21.274789Z
K 7
svn:log
V 488
sysutils/screen: fix coredump on xterm/rxvt variants without Km

On xterm- and rxvt-variants (and in some other cases) screen's
InitTermcap() tries to strdup() the terminals "Km" ("key_mouse")
termcap attribute - but that might be NULL, as some of these
terminals (notably rxvt and xterm-color) do not have "Km". Trying
to strdup() NULL results in segfault and coredump.
Catch that NULL and prevent the segfault.

PR:		241538
Reported by:	Marcin Cieślak, Gareth de Vaux
Approved by:	cy@

END