[PATCH v2 1/4] Replace 'test "${var+set}" = set' with '[ ${var+y} ]'

[Bernhard Reutner-Fischer]

The latter is faster to parse (let's say) and is already used in other
spots.

Tested with e.g. dash and busybox ash.
No regressions.

Please install.

2015-04-08  Bernhard Reutner-Fischer  <address@hidden>

        * lib/autoconf/general.m4 (_AC_ENABLE_IF_ACTION): Use
        '[ ${var+set} ]' instead of 'test "${var+set}" = set.
        (AC_CACHE_SAVE): Likewise.
        * lib/autoconf/lang.m4 (ac_link_default): Likewise.
        * lib/autoconf/programs.m4 (AC_PROG_INSTALL, AC_PROG_MKDIR_P): Likewise.
        * lib/autoconf/status.m4 (_AC_OUTPUT_MAIN_LOOP): Likewise.
        * lib/autotest/general.m4 (at_fn_create_debugging_script, Driver
        loop.): Likewise.
        * lib/m4sugar/m4sh.m4 (_AS_DETECT_BETTER_SHELL,
        _AS_SHELL_SANITIZE, _AS_PATH_SEPARATOR_PREPARE): Likewise.
        * tests/base.at (AC_CACHE_CHECK): Likewise.
        * tests/m4sh.at (LINENO stack): Use test "".

Signed-off-by: Bernhard Reutner-Fischer <address@hidden>
---
 lib/autoconf/general.m4  |    4 ++--
 lib/autoconf/lang.m4     |    2 +-
 lib/autoconf/programs.m4 |    4 ++--
 lib/autoconf/status.m4   |    8 ++++----
 lib/autotest/general.m4  |    4 ++--
 lib/m4sugar/m4sh.m4      |    8 ++++----
 tests/base.at            |    2 +-
 tests/m4sh.at            |    2 +-
 8 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/autoconf/general.m4 b/lib/autoconf/general.m4
index 2d1a291..adf4f39 100644
--- a/lib/autoconf/general.m4
+++ b/lib/autoconf/general.m4
@@ -1467,7 +1467,7 @@ _AC_ENABLE_IF_ACTION([$1], m4_translit([$2], [-+.], 
[___]), [$3], [$4])
 m4_define([_AC_ENABLE_IF_ACTION],
 [m4_append_uniq([_AC_USER_OPTS], [$1_$2], [
 ])dnl
-AS_IF([test "${$1_$2+set}" = set], [$1val=$$1_$2; $3], [$4])dnl
+AS_IF([[[ ${$1_$2+y} ]]], [$1val=$$1_$2; $3], [$4])dnl
 ])
 
 # AC_ARG_ENABLE(FEATURE, HELP-STRING, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
@@ -2044,7 +2044,7 @@ _AC_CACHE_DUMP() |
      /^ac_cv_env_/b end
      t clear
      :clear
-     s/^\([^=]*\)=\(.*[{}].*\)$/test "${\1+set}" = set || &/
+     s/^\([^=]*\)=\(.*[{}].*\)$/[ ${\1+y} ] || &/
      t end
      s/^\([^=]*\)=\(.*\)$/\1=${\1=\2}/
      :end'] >>confcache
diff --git a/lib/autoconf/lang.m4 b/lib/autoconf/lang.m4
index 2e30f50..bee633f 100644
--- a/lib/autoconf/lang.m4
+++ b/lib/autoconf/lang.m4
@@ -553,7 +553,7 @@ do
        # certainly right.
        break;;
     *.* )
-       if test "${ac_cv_exeext+set}" = set && test "$ac_cv_exeext" != no;
+       if [[ ${ac_cv_exeext+y} ]] && test "$ac_cv_exeext" != no;
        then :; else
           ac_cv_exeext=`expr "$ac_file" : ['[^.]*\(\..*\)']`
        fi
diff --git a/lib/autoconf/programs.m4 b/lib/autoconf/programs.m4
index 59df1a2..931177b 100644
--- a/lib/autoconf/programs.m4
+++ b/lib/autoconf/programs.m4
@@ -586,7 +586,7 @@ esac
 ])
 rm -rf conftest.one conftest.two conftest.dir
 ])dnl
-  if test "${ac_cv_path_install+set}" = set; then
+  if [[ ${ac_cv_path_install+y} ]]; then
     INSTALL=$ac_cv_path_install
   else
     # As a last resort, use the slow shell script.  Don't cache a
@@ -680,7 +680,7 @@ if test -z "$MKDIR_P"; then
         done
        done])])
   test -d ./--version && rmdir ./--version
-  if test "${ac_cv_path_mkdir+set}" = set; then
+  if [[ ${ac_cv_path_mkdir+y} ]]; then
     MKDIR_P="$ac_cv_path_mkdir -p"
   else
     # As a last resort, use the slow shell script.  Don't cache a
diff --git a/lib/autoconf/status.m4 b/lib/autoconf/status.m4
index ef9d521..7ccc847 100644
--- a/lib/autoconf/status.m4
+++ b/lib/autoconf/status.m4
@@ -1604,16 +1604,16 @@ AC_DEFUN([_AC_OUTPUT_MAIN_LOOP],
 # bizarre bug on SunOS 4.1.3.
 if $ac_need_defaults; then
 m4_ifdef([_AC_SEEN_CONFIG(FILES)],
-[  test "${CONFIG_FILES+set}" = set || CONFIG_FILES=$config_files
+[  [[ ${CONFIG_FILES+y} ]] || CONFIG_FILES=$config_files
 ])dnl
 m4_ifdef([_AC_SEEN_CONFIG(HEADERS)],
-[  test "${CONFIG_HEADERS+set}" = set || CONFIG_HEADERS=$config_headers
+[  [[ ${CONFIG_HEADERS+y} ]] || CONFIG_HEADERS=$config_headers
 ])dnl
 m4_ifdef([_AC_SEEN_CONFIG(LINKS)],
-[  test "${CONFIG_LINKS+set}" = set || CONFIG_LINKS=$config_links
+[  [[ ${CONFIG_LINKS+y} ]] || CONFIG_LINKS=$config_links
 ])dnl
 m4_ifdef([_AC_SEEN_CONFIG(COMMANDS)],
-[  test "${CONFIG_COMMANDS+set}" = set || CONFIG_COMMANDS=$config_commands
+[  [[ ${CONFIG_COMMANDS+y} ]] || CONFIG_COMMANDS=$config_commands
 ])dnl
 fi
 
diff --git a/lib/autotest/general.m4 b/lib/autotest/general.m4
index e70e326..59242ab 100644
--- a/lib/autotest/general.m4
+++ b/lib/autotest/general.m4
@@ -363,7 +363,7 @@ at_fn_create_debugging_script ()
 {
   {
     echo "#! /bin/sh" &&
-    echo 'test "${ZSH_VERSION+set}" = set dnl
+    echo '[[ ${ZSH_VERSION+y} ]] dnl
 && alias -g '\''${1+"address@hidden"}'\''='\''"address@hidden"'\''' &&
     AS_ECHO(["cd '$at_dir'"]) &&
     AS_ECHO(["exec \${CONFIG_SHELL-$SHELL} \"$at_myself\" -v -d ]dnl
@@ -1367,7 +1367,7 @@ dnl Unfortunately, ksh93 fork-bombs when we send TSTP, so 
send STOP
 dnl if this might be ksh (STOP prevents possible TSTP handlers inside
 dnl AT_CHECKs from running).  Then stop ourselves.
          at_sig=TSTP
-         test "${TMOUT+set}" = set && at_sig=STOP
+         [[ ${TMOUT+y} ]] && at_sig=STOP
          kill -$at_sig $at_pids 2>/dev/null
        fi
        kill -STOP $$
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 603466f..1bdf21c 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -100,7 +100,7 @@ _$0
 # This is the part of AS_BOURNE_COMPATIBLE which has to be repeated inside
 # each instance.
 m4_define([_AS_BOURNE_COMPATIBLE],
-[AS_IF([test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1],
+[AS_IF([test -n "${ZSH_VERSION+y}" && (emulate sh) >/dev/null 2>&1],
  [emulate sh
   NULLCMD=:
   [#] Pre-4.2 versions of Zsh do word splitting on ${1+"address@hidden"}, which
@@ -252,7 +252,7 @@ dnl Unfortunately, $as_me isn't available here.
     AS_IF([test x$as_have_required = xno],
       [AS_ECHO(["$[]0: This script requires a shell more modern than all"])
   AS_ECHO(["$[]0: the shells that I found on your system."])
-  if test x${ZSH_VERSION+set} = xset ; then
+  if [[ ${ZSH_VERSION+y} ]]; then
     AS_ECHO(["$[]0: In particular, zsh $ZSH_VERSION has bugs and should"])
     AS_ECHO(["$[]0: be upgraded to zsh 4.3.4 or later."])
   else
@@ -488,7 +488,7 @@ fi
 # suppresses any "Segmentation fault" message there.  '((' could
 # trigger a bug in pdksh 5.2.14.
 for as_var in BASH_ENV ENV MAIL MAILPATH
-do eval test x\${$as_var+set} = xset \
+do eval [[ \${$as_var+y} ]] \
   && ( (unset $as_var) || exit 1) >/dev/null 2>&1 && unset $as_var || :
 done
 PS1='$ '
@@ -1272,7 +1272,7 @@ fi
 # Compute the path separator.
 m4_defun([_AS_PATH_SEPARATOR_PREPARE],
 [# The user is always right.
-if test "${PATH_SEPARATOR+set}" != set; then
+if [[ ! ${PATH_SEPARATOR+y} ]]; then
   PATH_SEPARATOR=:
   (PATH='/bin;/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 && {
     (PATH='/bin:/bin'; FPATH=$PATH; sh -c :) >/dev/null 2>&1 ||
diff --git a/tests/base.at b/tests/base.at
index 63bd36e..699d146 100644
--- a/tests/base.at
+++ b/tests/base.at
@@ -342,7 +342,7 @@ my_cv_variable=true
 AC_MSG_RESULT([$my_cv_variable])
 
 # Ensure that the result is available at this point.
-if test ${my_cv_variable+set} != set; then
+if [[ ! "${my_cv_variable+y}" ]]; then
   AC_MSG_ERROR([AC@&@&address@hidden@_CACHE_VAL did not ensure that the cache 
variable was set])
 fi
 
diff --git a/tests/m4sh.at b/tests/m4sh.at
index df39ae7..6f68b28 100644
--- a/tests/m4sh.at
+++ b/tests/m4sh.at
@@ -297,7 +297,7 @@ test $as_lineno = 9999 || AS_ERROR([bad as_lineno at depth 
2])
 AS_LINENO_POP
 test $as_lineno = 9999 || AS_ERROR([bad as_lineno at depth 1])
 AS_LINENO_POP
-test x${as_lineno+set} = xset && AS_ERROR([as_lineno set at depth 0])
+test "${as_lineno+y}" && AS_ERROR([as_lineno set at depth 0])
 
 AS_EXIT([0])
 ]])
-- 
1.7.10.4