[PATCH 8/10] Check that stdout variable is not null

[William Hahne]

BootX will sometimes set the stdout variable to null and then subsequently
call io-emit which can eventually result in an infinite loop.

Index: forth/admin/iocontrol.fs
===================================================================
--- forth/admin/iocontrol.fs (revision 1041)
+++ forth/admin/iocontrol.fs (working copy)
@@ -80,6 +80,7 @@
 ;

: io-emit ( char -- )
+  stdout @ 0= if drop exit then \ make sure stdout pointer is not null
   io-out-char c!
   io-out-char 1 " write" stdout @ $call-method drop
 ;