CVS commit: [netbsd-9] src/usr.bin/ftp

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Mon Jun 14 11:22:16 UTC 2021

Modified Files:
        src/usr.bin/ftp [netbsd-9]: ftp.c version.h

Log Message:
Pull up following revision(s) (requested by lukem in ticket #1290):

        usr.bin/ftp/version.h: revision 1.90
        usr.bin/ftp/ftp.c: revision 1.170

ftp.c: improve signal handler restoration

Only invoke the old signal handler if it's a real signal handler
and not SIG_IGN, SIG_DFL, SIG_HOLD, or SIG_ERR, using new static
function issighandler().

Avoids an intermittent race condition with a null pointer
dereference via (*SIG_DFL)().

Bug class reported by Joyu Liao from Juniper Networks.

Use SIG_ERR instead of NULL as the indicator that a signal handler
hasn't been changed, so that SIG_DFL (equivalent to NULL)
will be restored.


To generate a diff of this commit:
cvs rdiff -u -r1.168.2.1 -r1.168.2.2 src/usr.bin/ftp/ftp.c
cvs rdiff -u -r1.87.18.1 -r1.87.18.2 src/usr.bin/ftp/version.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.