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, 11 insertions, 9 deletions

diff --git a/t/self-check-exit.tap b/t/self-check-exit.tap
index 0ad5651a1..e78ca0b2f 100755
--- a/t/self-check-exit.tap
+++ b/t/self-check-exit.tap
@@ -20,7 +20,7 @@
 # Also check that the 'errexit' shell flag is active.
 
 am_create_testdir=no
-. ./defs || Exit 99
+. ./defs || exit 99
 
 plan_ 34
 
@@ -35,15 +35,17 @@ AM_TESTS_REEXEC=no; export AM_TESTS_REEXEC
 # ./defs, i.e., when 'set -e' is not active yet, for the benefit of shells
 # (like Bash 2.05 and Solaris 10 /bin/ksh) that returns a non-zero status
 # when unsetting an already-unset variable.
-init='stderr_fileno_=2; unset am_explicit_skips; . ./defs'
+# Add an extra newline at the end so that the aliases defined by 'defs'
+# can take effect.  Yes, this is truly required.
+init="stderr_fileno_=2; unset am_explicit_skips; . ./defs${nl}"
 
 # Required so that the code in defs doesn't go crazy trying to creating a
 # temporary directory in the absolute dir of $AM_TEST_RUNNER_SHELL.
 dummy_test_script=t/$me.sh
 
 for st in 1 2 3 4 5 77 99 126 127 128 129 130 255; do
-  for exit_cmd in "Exit $st" "sh -c 'exit $st'"; do
-    $AM_TEST_RUNNER_SHELL -c "$init; $exit_cmd; :" "$dummy_test_script"
+  for exit_cmd in "exit $st" "sh -c 'exit $st'"; do
+    $AM_TEST_RUNNER_SHELL -c "$init $exit_cmd; :" "$dummy_test_script"
     command_ok_ "$exit_cmd" test $? -eq $st
   done
 done
@@ -59,7 +61,7 @@ for sig in 1 2 13 15; do
     # <http://lists.gnu.org/archive/html/bug-autoconf/2011-09/msg00004.html>
     trap : 2
   fi
-  $AM_TEST_RUNNER_SHELL -c "$init; kill -$sig \$\$; :" "$dummy_test_script"
+  $AM_TEST_RUNNER_SHELL -c "$init kill -$sig \$\$; :" "$dummy_test_script"
   rc=$?
   if test $sig -eq 2; then
     # Reset default SIGINT handler as portably as possible.
@@ -84,20 +86,20 @@ if $AM_TEST_RUNNER_SHELL -c 'set -e; trap "exit \$?" 0; non-existent-program'; t
 else
   maybe_todo="" reason=""
 fi
-$AM_TEST_RUNNER_SHELL -c "$init; non-existent-prog; :" "$dummy_test_script"
+$AM_TEST_RUNNER_SHELL -c "$init non-existent-prog; :" "$dummy_test_script"
 command_ok_ "command not found" -D "$maybe_todo" -r "$reason" \
             -- test $? -gt 0
 
 : Non-executable command.
 test -f Makefile && test ! -x Makefile || \
   framowork_failure_ "no proper Makefile in the current directory"
-$AM_TEST_RUNNER_SHELL -c "$init; ./Makefile; :" "$dummy_test_script"
+$AM_TEST_RUNNER_SHELL -c "$init ./Makefile; :" "$dummy_test_script"
 command_ok_ "permission denied" test $? -gt 0
 
 : Syntax errors in the test code.
-$AM_TEST_RUNNER_SHELL -c "$init; if :; then" "$dummy_test_script"
+$AM_TEST_RUNNER_SHELL -c "$init if :; then" "$dummy_test_script"
 command_ok_ "syntax error 1" test $? -gt 0
-$AM_TEST_RUNNER_SHELL -c "$init; true ( true )" "$dummy_test_script"
+$AM_TEST_RUNNER_SHELL -c "$init true ( true )" "$dummy_test_script"
 command_ok_ "syntax error 2" test $? -gt 0
 
 :