+++ This bug was initially created as a clone of Bug #1217236 +++
To test, either have ksh as login shell, or create a test user.
Then ssh localhost.
$ cd /tmp/alan
$ cat tst.ksh
echo $D > /tmp/alan/tst.dat
$ (ksh /tmp/alan/tst.ksh &)
This happens due to a double fork, once for "( cmd )" and
then the first fork forks again due to the "&", but, just
when the child branches, it receives a SIGHUP and
I tested a quick&dirty patch, that basically reverts to
rhel5 ksh behavior, and there are no regressions in the
diff -up ksh-20120801/src/cmd/ksh93/sh/xec.c.orig ksh-20120801/src/cmd/ksh93/sh/xec.c
--- ksh-20120801/src/cmd/ksh93/sh/xec.c.orig 2015-04-28 16:55:25.521818636 -0300
+++ ksh-20120801/src/cmd/ksh93/sh/xec.c 2015-04-28 16:56:34.037753565 -0300
@@ -2059,16 +2059,20 @@ int sh_exec(register const Shnode_t *t,
else if(((type=t->par.partre->tre.tretyp)&FAMP) && ((type&COMMSK)==TFORK))
I also asked upstream, see http://lists.research.att.com/pipermail/ast-users/2015q2/004754.html
but actually, there is a bad comment there, about crashes if
running it as "( cmd ) &". Likely it was due to the way I was
Note that if one has bash as login shell, then starts, or exec
ksh, or even if has ksh as login shell, and first exec ksh,
it will work, because then SIGHUP will be blocked in the
"orphan" process (orphan due to double fork).
Reported for rawhide, but happens in all non EOL
This bug appears to have been reported against 'rawhide' during the Fedora 23 development cycle.
Changing version to '23'.
(As we did not run this process for some time, it could affect also pre-Fedora 23 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 23 End Of Life. Thank you.)
More information and reason for this action is here:
This bug is a regression of a fix that upstream made:
10-09-21 A bug in the processing of (command&) which created a job in the
parent process has been fixed.
and exactly the commented-out code was added as the fix (original code also did a backup and restoration of sh.bckpid around sh_exec. So we can't just revert that change.