Re: [coreutils] Re: Builds of coreutils-8.6.19-1369f

[Jim Meyering]

Ralf Wildenhues wrote:

> * Jim Meyering wrote on Sat, Nov 06, 2010 at 06:14:05PM CET:
>> Ralf Wildenhues wrote:
>> > - Posix does not require IFS to be set upon script startup.  It only 
>> > requires
>> > that, if IFS is unset, word splitting ought to behave as if it were set to
>> > space, tab, and newline, in that order.  That is why the startup code of 
>> > all
>> > autotools scripts explicitly sets IFS, so that saving and restoring works.
>>
>> Thanks.  That's good to know, but it appears not to be an issue
>> for any shell that gets past the init.sh tests.
>
> Are you sure?  It affects any test that saves and restores IFS in any
> way.

No, but it looks that way.
When the new FreeBSD 8.1 /bin/sh "local" issue makes it so IFS is
not restored, coreutils gets numerous failures.

I've never seen that before.
It looks like both of the other IFS-restoring coreutils tests would
fail if IFS restoration failed.

    $ git grep -w IFS|grep -E 'old|save'
    old/fileutils/ChangeLog:        * tests/mkdir/perm: Don't put a newline\
       in IFS;  that's not portable to
    tests/chmod/usage:old_IFS=$IFS
    tests/chmod/usage:  IFS=$old_IFS
    tests/init.cfg:  local saved_IFS="$IFS"
    tests/init.cfg:  IFS=$saved_IFS
    tests/mkdir/perm:  old_IFS=$IFS
    tests/mkdir/perm:  IFS=$old_IFS

Do you know of a modern shell that acts as you describe?
I've run the following on a decent selection of systems,
and saw no failure:

for sh in sh bash ksh pdksh dash zsh; do
  type $sh > /dev/null || continue;
  $sh -c 'i=$IFS; test -n "$IFS"' || echo fail
done

If some shell does fail, perhaps init.sh should use a patch like the following.
I hesitate to add code like this, unless there's at least one
known system where it makes a difference.

diff --git a/tests/init.sh b/tests/init.sh
index a57de77..a37d129 100644
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -330,6 +330,12 @@ setup_()
     || fail_ "failed to create temporary directory in $initial_cwd_"
   cd "$test_dir_"

+  # As autoconf-generated configure scripts do, ensure that IFS is defined
+  # initially, so that saving and restoring $IFS works.
+  gl_init_sh_nl_='
+'
+  IFS=" ""     $gl_init_sh_nl_"
+
   # This trap statement, along with a trap on 0 below, ensure that the
   # temporary directory, $test_dir_, is removed upon exit as well as
   # upon receipt of any of the listed signals.