bin/180146: /bin/sh: Early SIGWINCH can end process

[Grant Watson]

>Number:         180146
>Category:       bin
>Synopsis:       /bin/sh: Early SIGWINCH can end process
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jul 01 03:10:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Grant Watson
>Release:        9.1-RELEASE
>Organization:
>Environment:
FreeBSD awesome-bsd 9.1-RELEASE FreeBSD 9.1-RELEASE #0 r243825: Tue Dec 4 09:23:10 UTC 2012 root at farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64
>Description:
There appears to be a race condition in /bin/sh where receiving
SIGWINCH too early will cause the process to end.  Bugs ports/178194
and ports/178651, which I filed, are occurrences of this bug.
>How-To-Repeat:
Way to Reproduce #1:

Install termit and paste the following into ~/.config/termit/rc.lua:

    defaults = {
        showScrollbar = false,
        hideMenubar = true
    }
    setOptions(defaults)

Then run "termit -e /bin/sh".  Running "termit -e 'truss -o shlog.txt /bin/sh'" does not surpress the bug for me.

Way to Reproduce #2:

Install the awesome window manager, create a user whose shell is /bin/sh, and ensure that this user does not have a ~/.config/awesome/rc.lua file that would override the default configuration.

Log in as this user.  Left click the box in the upper-right corner of the screen to switch to a tiling layout.  Press super+return (that is, windows+return) four or five times; each time an xterm should open.  Many will close, but one or two may remain open.  Running "truss xterm -e /bin/sh" does not surpress the bug for me, but running truss between xterm and sh does.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: