ksh segfaults if unset running function from another one

Issue

• When leaving function which was unset in the meantime ksh segfaults on the line:
• Steps to Reproduce:

1. create a script test.sh:
#!/bin/ksh

function ftest {
        ftest2
}


function ftest2 {
        unset -f ftest
}

ftest


2. run the script

Actual results:

Segmentation fault (core dumped)