Re: [PATCH] Fix exit status of signal handlers in shell scripts

[Dmitry V. Levin]

On Sun, Jan 31, 2010 at 01:51:59AM +0100, Bruno Haible wrote:
> Additionally, another proposed change prompted by Dmitry's patch.
> 
> The Autoconf manual
> <http://www.gnu.org/software/autoconf/manual/html_node/Shell-Functions.html>
> says:
>   "the state of ‘$?’ is not reliable when entering a shell function. This has
>    the effect that using a function as the first command in a trap handler can
>    cause problems."
> 
> Here's a proposed fix (need to handle the same problem in bootstrap yourself):
> 
> 
> 2010-01-30  Bruno Haible  <address@hidden>
> 
>       Avoid unportable use of $? at the beginning of a shell function.
>       * tests/init.sh (remove_tmp_): Don't deal with exit status here.
>       (setup_): Do it directly in the trap handler here.
> 
> --- tests/init.sh.orig        Sun Jan 31 01:46:23 2010
> +++ tests/init.sh     Sun Jan 31 01:46:09 2010
> @@ -82,14 +82,12 @@
>  # directory and exit with the incoming value of $?.
>  remove_tmp_()
>  {
> -  __st=$?
>    cleanup_
>    # cd out of the directory we're about to remove
>    cd "$initial_cwd_" || cd / || cd /tmp
>    chmod -R u+rwx "$test_dir_"
>    # If removal fails and exit status was to be 0, then change it to 1.
>    rm -rf "$test_dir_" || { test $__st = 0 && __st=1; }
> -  exit $__st

This would break the "If removal fails" statement.
Let's pass exit code to this function as an argument:

remove_tmp_()
{
  __st=$1
  [...]
  trap 'remove_tmp_ $?' 0


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