tests: simpler workaround for shells losing the exit status in exit trap

Now that we can assume our tests are run by a decent POSIX shell, we
can simplify our workaround aimed at having the exit status propagated
correctly to the code in the exit trap.  Unfortunately, we cannot
dispense with such a workaround altogether, because it's still required
by some shells we need to support (at least Solaris 10 /bin/ksh and
/usr/xpg4/bin/sh).

For more information about the need of that workaround, see the entry
about 'trap' in the section "Limitations of Shell Builtins" in the
Autoconf manual:
<http://www.gnu.org/software/autoconf/manual/autoconf.html#trap>

The new workaround has been tested successfully with the following
shells:

  - Bash 4.1
  - Bash 3.2
  - Bash 3.0
  - Bash 2.05b
  - dash 0.5.5.1
  - dash 0.5.2
  - AT&T Ksh 93u (from official Debian package)
  - MirBSD Korn Shell 40.2 (from official Debian package)
  - Solaris 9, 10 and 11 /bin/ksh
  - Solaris 9, 10 and 11 /usr/xpg4/bin/sh
  - NetBSD 5.1 /bin/sh
  - NetBSD 5.1 /bin/ksh

* t/ax/test-init.sh (Exit): Rename ...
(_am_exit): ... like this.
(exit): New alias for '_am_exit'.  We cannot simply redefine 'exit'
as a shell function, because some shells (dash 0.5.5.1, Solaris 10
/bin/ksh and /usr/xpg4/bin/sh) do not allow it.
(_am_exit, trap): Add extra escaping for 'exit' calls, to ensure we
really invoke the 'exit' builtin and not our alias with the same
name.
* configure.ac: Check that the shell selected to run our testsuite
supports aliases named like shell builtins.
* t/REAMDE: Adjust.
* All tests: Adjust, by simply using 'exit' instead of 'Exit'.
* t/self-check-explicit-skips.sh: Adjust: the first usage of 'exit'
after it has been redefined as an alias must be on a new line w.r.t.
that where the alias is defined, in order for the redefinition to be
honored.
* syntax-checks.mk (sc_tests_Exit_not_exit): Delete.
(sc_tests_exit_not_Exit): New.
(syntax_check_rules): Adjust.
(sc_tests_automake_fails): Simplify the recipe a little.
* Several tests: Remove now useless spurious quoting once required
to placate the 'sc_tests_Exit_not_exit' maintainer check.
* gen-testsuite-part: Likewise.  Also, avoid uses of 'Exit' in the
generated scripts.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/t/distcheck-configure-flags-subpkg.sh b/t/distcheck-configure-flags-subpkg.sh
index 45d0e0cb6..f5bc15d26 100755
--- a/t/distcheck-configure-flags-subpkg.sh
+++ b/t/distcheck-configure-flags-subpkg.sh
@@ -20,7 +20,7 @@
 # passed down to the configure script of the subpackage.  This is
 # explicitly documented in the manual.
 
-. ./defs || Exit 1
+. ./defs || exit 1
 
 cat >> configure.ac << 'END'
 AC_CONFIG_SUBDIRS([subpkg])
@@ -63,7 +63,7 @@ $FGREP 'DISTCHECK_CONFIGURE_FLAGS' Makefile.in subpkg/Makefile.in
 
 grep '^AM_DISTCHECK_CONFIGURE_FLAGS =' Makefile.in
 grep '^DISTCHECK_CONFIGURE_FLAGS =' Makefile.in
-$EGREP '^(AM_)?DISTCHECK_CONFIGURE_FLAGS' subpkg/Makefile.in && Exit 1
+$EGREP '^(AM_)?DISTCHECK_CONFIGURE_FLAGS' subpkg/Makefile.in && exit 1
 
 ./configure dc=ok am_dc=ok
 
@@ -74,7 +74,7 @@ $MAKE distcheck
 
 # ... but not when "make distcheck" is run from the subpackage.
 cd subpkg
-$MAKE distcheck >output 2>&1 && { cat output; Exit 1; }
+$MAKE distcheck >output 2>&1 && { cat output; exit 1; }
 cat output
 grep '^configure:.* dc=KO am_dc=KO' output