segmentation fault

mksh segfaults

# mksh -c 'echo ${0/}'
Segmentation fault

(gdb) run -c 'echo ${0/}'
Starting program: /root/fuzzshell/mksh -c 'echo ${0/}'

Program received signal SIGSEGV, Segmentation fault.
0x0804ba3c in findptr (ap=0x201b60, ptr=0x8201a7c "/root/fuzzshell/mksh", lpp=<synthetic pointer>) at ../../lalloc.c:59
59		while (ap->next != lp)
(gdb) bt
#0  0x0804ba3c in findptr (ap=0x201b60, ptr=0x8201a7c "/root/fuzzshell/mksh", lpp=<synthetic pointer>) at ../../lalloc.c:59
#1  aresize (ptr=0x8201a7c, numb=21, ap=0x82019ac) at ../../lalloc.c:93
#2  0x0804fe66 in expand (ccp=0x820199e "", wp=0xbffe6ab4, f=<optimized out>) at ../../eval.c:905
#3  0x0805c43e in eval (ap=0x82018cc, f=11) at ../../eval.c:147
#4  0x08065b0f in execute (t=0x820196c, flags=0, xerrok=0xbffe6b0c) at ../../exec.c:140
#5  0x080c8579 in shell (s=0x82014f4, toplevel=<optimized out>) at ../../main.c:844
#6  0x0804a436 in main (argc=3, argv=0xbffe6dd4) at ../../main.c:654
(gdb) 

echo $KSH_VERSION

@(#)MIRBSD KSH R52 2016/01/20