[ast-developers] ksh does not fork a subshell and breaks wait builtin

[Siteshwar Vashisht]

Reproducer Steps :

1. Download attached file subshell.tar
2. Extract it and run ./subshell_test.ksh

Actual Result :

$ ./subshell_test.ksh
ksh Version AJM 93u+ 2012-08-01
Wed Jan 11 12:39:33 GMT 2017 Start ---------------------- subshell_test.ksh ----------------------
Wed Jan 11 12:39:33 GMT 2017 Start ---------------------- subshellA1.ksh ----------------------
Wed Jan 11 12:39:33 GMT 2017 Start ---------------------- subshellA2.ksh ----------------------
Wed Jan 11 12:39:33 GMT 2017 Start ---------------------- subshellA3.ksh ----------------------
Wed Jan 11 12:39:33 GMT 2017 Start ---------------------- watchdog_timer.ksh ----------------------
Wed Jan 11 12:41:13 GMT 2017 End ---------------------- subshellA3.ksh ----------------------
Wed Jan 11 12:42:53 GMT 2017 End ---------------------- subshellA2.ksh ----------------------
Wed Jan 11 12:44:33 GMT 2017 End ---------------------- subshellA1.ksh ----------------------
Wed Jan 11 12:46:13 GMT 2017 End ---------------------- watchdog_timer.ksh ----------------------
subshell_test.ksh has overrun its time of 6 minutes
Started by:
UID PID PPID C STIME TTY TIME CMD
<<user>> 17090 4104 0 12:39 pts/8 00:00:00 /bin/ksh ./subshell_test.ksh
Wed Jan 11 12:46:13 GMT 2017 Start ---------------------- extra_task.ksh ----------------------
Wed Jan 11 12:47:53 GMT 2017 End ---------------------- extra_task.ksh ----------------------
Wed Jan 11 12:47:53 GMT 2017 End ---------------------- subshell_test.ksh ----------------------


Expected Result :

$ ./subshell_test.ksh
ksh Version AJM 93t+ 2010-06-21
Wed Jan 11 12:38:11 GMT 2017 Start ---------------------- subshell_test.ksh ----------------------
Wed Jan 11 12:38:11 GMT 2017 Start ---------------------- subshellA1.ksh ----------------------
Wed Jan 11 12:38:11 GMT 2017 Start ---------------------- subshellA2.ksh ----------------------
Wed Jan 11 12:38:11 GMT 2017 Start ---------------------- subshellA3.ksh ----------------------
Wed Jan 11 12:38:11 GMT 2017 Start ---------------------- watchdog_timer.ksh ----------------------
Wed Jan 11 12:39:51 GMT 2017 End ---------------------- subshellA3.ksh ----------------------
Wed Jan 11 12:41:31 GMT 2017 End ---------------------- subshellA2.ksh ----------------------
Wed Jan 11 12:43:11 GMT 2017 End ---------------------- subshellA1.ksh ----------------------
Wed Jan 11 12:43:11 GMT 2017 Start ---------------------- extra_task.ksh ----------------------
Wed Jan 11 12:44:51 GMT 2017 End ---------------------- extra_task.ksh ----------------------
Wed Jan 11 12:44:51 GMT 2017 End ---------------------- subshell_test.ksh ----------------------
<< SHELL_PROMPT >>
$ Wed Jan 11 12:44:51 GMT 2017 End ---------------------- watchdog_timer.ksh ----------------------


Attached patch fixes this bug.