Bug#795954: sysconfig-hardware contains various syntax errors in "case" commands

[Philipp Kern]

On Tue, Aug 18, 2015 at 06:07:57AM -0400, Stephen Powell wrote:
> The sysconfig-hardware package contains a number of syntax errors in "case"
> commands.  The "case" command requires that after each pattern specification
> there must be a command list, and this command list must be terminated by
> a double semicolon. 

This is incorrect if you look at POSIX:

  The compound-list for each list of patterns, with the possible exception
  of the last, shall be terminated with ";;".

http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
  "Case Conditional Construct"

> In some places, the only thing between the end of the pattern
> specification and the double semicolon is a comment.  A comment is not
> a list.  A null command (a colon) will do, but there must be at least
> one command present to constitute a list.  In other places, there is
> no double semicolon to terminate the list.  This also is a violation
> of the rules of valid syntax.

Well, all of the scripts declare that they are run with bash. It's
clearer to pass in the : built-in and I couldn't find language lawyering
that would allow the empty compound-list here at first glance, but it's
also highly unlikely that bash will change in a fashion that forbids
this.

To improve correctness it makes sense to apply the patch.

Kind regards
Philipp Kern


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Bug#795954: sysconfig-hardware contains various syntax errors in "case" commands

[Stephen Powell]

On Sat, 05 Sep 2015 13:51:22 -0400 (EDT), Philipp Kern wrote:
> 
> This is incorrect if you look at POSIX:
> 
>   The compound-list for each list of patterns, with the possible exception
>   of the last, shall be terminated with ";;".
> 
> http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
>   "Case Conditional Construct"

I wasn't looking at POSIX, I was looking at "man bash".  bash supports
two alternate delimiters to ";;", namely, ";&", and ";;&", but use of
these delimiters alters subsequent behavior.  I could find nowhere in
the documentation for the case command in "man bash" which stated that
the delimiter could be eliminated entirely under any conditions.  Note
that the two alternate delimiters I mentioned are *not* POSIX compliant.
> 
> Well, all of the scripts declare that they are run with bash. It's
> clearer to pass in the : built-in and I couldn't find language lawyering
> that would allow the empty compound-list here at first glance, but it's
> also highly unlikely that bash will change in a fashion that forbids
> this.

Again, "man bash" states:

   "A list is a sequence of one or more pipelines ..."

Notice that the definition says "one or more pipelines", not "zero or more
pipelines".  Interestingly enough, "man dash" *does* say "zero or more
pipelines".  But sysconfig-hardware requires bash.  I tried once to convert
it to dash, but ran into problems with array assignment statements that
I didn't know how to convert, and decided to leave well enough alone.
> 
> To improve correctness it makes sense to apply the patch.

I agree.

-- 
  .''`. Stephen Powell
 : :'  :
 `. `'`
   `-

Bug#795954: sysconfig-hardware contains various syntax errors in case commands

[Stephen Powell]

Package: sysconfig-hardware
Version: 0.0.10+nmu1
Severity: minor
Tags: patch
X-Debbugs-CC: debian-s...@lists.debian.org

The sysconfig-hardware package contains a number of syntax errors in case
commands.  The case command requires that after each pattern specification
there must be a command list, and this command list must be terminated by
a double semicolon.  This is violated in several places.  In some places,
the only thing between the end of the pattern specification and the double
semicolon is a comment.  A comment is not a list.  A null command (a colon)
will do, but there must be at least one command present to constitute a list.
In other places, there is no double semicolon to terminate the list.  This
also is a violation of the rules of valid syntax.

For some reason, the code has apparently been executing more or less correctly;
but a future release of bash (yes, bash, not dash) may tighten up standards
and the code will fail.  I have attached a patch file which corrects the
problems.

Note: the portion of the patch which changes chandev-convert affects only
the source package.  It is not included in the binary package.

-- 
  .''`. Stephen Powellzlinux...@wowway.com
 : :'  :
 `. `'`
   `-diff -uar a/etc/sysconfig/scripts/hardware/functions b/etc/sysconfig/scripts/hardware/functions
--- a/etc/sysconfig/scripts/hardware/functions	2010-10-30 10:50:49.0 -0400
+++ b/etc/sysconfig/scripts/hardware/functions	2015-08-18 05:36:06.411307488 -0400
@@ -27,6 +27,7 @@
   echo $SCRIPTNAME: illegal option -- $OPTARG 2
   echo Try: \`$SCRIPTNAME -h' for mor information. 2
   exit $R_USAGE
+  ;;
 esac
   done
 
diff -uar a/etc/sysconfig/scripts/hardware/hwup b/etc/sysconfig/scripts/hardware/hwup
--- a/etc/sysconfig/scripts/hardware/hwup	2010-10-30 10:28:43.0 -0400
+++ b/etc/sysconfig/scripts/hardware/hwup	2015-08-18 05:38:22.536360188 -0400
@@ -17,6 +17,7 @@
 case ${STARTMODE:-auto}:$MODE in
   auto:auto|*:auto-override)
   # Start auto devices in auto and override mode.
+  :
   ;;
   *:auto)
   # Don't display any message if device is not auto in auto mode.
@@ -24,6 +25,7 @@
   ;;
   auto:manual|manual:manual)
   # Start manual devices in manual mode.
+  :
   ;;
   off:manual)
   message $SCRIPTNAME: used configuration has STARTMODE=$STARTMODE.
@@ -32,6 +34,7 @@
   *)
   message $SCRIPTNAME: unknown STARTMODE=$STARTMODE.
   exit $R_ERROR
+  ;;
 esac
 
 source $SYSCONFIG/scripts/hardware/$COMMAND-$BUS $ID $DEVPATH
diff -uar a/usr/share/sysconfig/chandev-convert b/usr/share/sysconfig/chandev-convert
--- a/usr/share/sysconfig/chandev-convert	2009-03-24 06:10:51.0 -0400
+++ b/usr/share/sysconfig/chandev-convert	2015-08-18 05:40:58.760978505 -0400
@@ -26,6 +26,7 @@
 echo $SCRIPTNAME: illegal option -- $OPTARG 2
 echo Try: \`$SCRIPTNAME -h' for mor information. 2
 exit $R_USAGE
+;;
   esac
 done