This fix was developed inhouse on top of the ksh93 alpha version(2013-10-10-alpha).
This has been submitted to the community but not been accepted yet.
Details can be found at
https://github.com/att/ast/issues/5
--- INIT.2011-02-08.old/src/cmd/ksh93/sh/macro.c 2015-05-04 13:33:02.298225000 -0700
+++ INIT.2011-02-08/src/cmd/ksh93/sh/macro.c 2015-06-03 13:20:45.726236100 -0700
@@ -1195,6 +1195,13 @@
}
else
v = 0;
+ if(!v && sh_isoption(SH_NOUNSET))
+ {
+ d=fcget();
+ fcseek(-1);
+ if(d=='\0' || !strchr(":+-?=",d))
+ errormsg(SH_DICT,ERROR_exit(1),e_notset,ltos(c));
+ }
break;
case S_ALP:
if(c=='.' && type==0)