conf/175079: rc.subr poorly handles recursive run_rc_command invocations

[Yuriy Taraday]

>Number:         175079
>Category:       conf
>Synopsis:       rc.subr poorly handles recursive run_rc_command invocations
>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:   Sun Jan 06 23:10:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Yuriy Taraday
>Release:        8.3-RELEASE-p5
>Organization:
>Environment:
reeBSD greater 8.3-RELEASE-p5 FreeBSD 8.3-RELEASE-p5 #1: Wed Dec 12 15:30:21 GST 2012     root at greater:/usr/obj/usr/src/sys/MYCONF  amd64
>Description:
When custom precmd or cmd calls run_rc_command, postcmd and/or cmd are most likely to be missed.
For example, when squid stop_cmd calls "run_rc_command poll", _postcmd variable is overwritten and my postcmd was never called.
>How-To-Repeat:
Add your custom stop_postcmd for squid in /etc/rc.conf.d/squid. It will never be called.
>Fix:
Proposed patch makes these variables local to function so that they are not overwritten in caller's namespace.

Patch attached with submission follows:

*** /usr/src/etc/rc.subr	2012-03-03 10:15:13.000000000 +0400
--- /etc/rc.subr	2013-01-07 02:48:43.000000000 +0400
*************** run_rc_command()
*** 717,722 ****
--- 717,723 ----
  					# if there's a custom ${XXX_cmd},
  					# run that instead of the default
  					#
+ 		local _cmd _precmd _postcmd
  		eval _cmd=\$${rc_arg}_cmd \
  		     _precmd=\$${rc_arg}_precmd \
  		     _postcmd=\$${rc_arg}_postcmd


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