delete trailing whitespace from control files

[debian/gzip] / m4 / shell.m4

diff --git a/m4/shell.m4 b/m4/shell.m4
index 2b10bb07f6fdeb58bc2bfa6543214a366cb6be8d..f9ca24edca84ce777d5ef0c90516d5baf2ddd579 100644 (file)
--- a/m4/shell.m4
+++ b/m4/shell.m4
@@ -1,6 +1,6 @@
 # Check for a working shell.
 
-# Copyright (C) 2000-2001, 2007, 2009-2010 Free Software Foundation, Inc.
+# Copyright (C) 2000-2001, 2007, 2009-2018 Free Software Foundation, Inc.
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 3, or (at your option)
@@ -25,52 +25,65 @@ AC_DEFUN([AC_PROG_SHELL],
   [AC_MSG_CHECKING([for a POSIX-compliant shell])
    AC_CACHE_VAL(ac_cv_path_shell,
      [ac_command='
-       # Test the noclobber option, using the portable POSIX.2 syntax.
-       set -C
-       rm -f conftest.c
-       >conftest.c || exit
-       >|conftest.c || exit
-       !>conftest.c || exit
-       # Test that $(...) works.
-       test "$(expr 3 + 4)" -eq 7 || exit
+        # Test the noclobber option, using the portable POSIX.2 syntax.
+        set -C
+        rm -f conftest.c
+        >conftest.c || exit
+        >|conftest.c || exit
+        !>conftest.c || exit
+        # Test that $(...) works.
+        test "$(expr 3 + 4)" -eq 7 || exit
       '
+      # Solaris 11 /bin/sh (AT&T Research) 93u 2011-02-08 has a file
+      # descriptor bug that breaks zgrep and is hard to test for
+      # directly.  At some point $(...) is reading a pipe from the
+      # subshell, but the pipe is also open in the parent shell, so
+      # the read deadlocks.  Prefer some other shell if available.
+      ac_maybe_solaris_sh_bug='test "${.sh.version}"'
+
       ac_cv_path_shell=no
 
       case $SHELL in
-      (/*)
-       rm -f conftest.c
-       if ("$SHELL" -c "$ac_command") 2>/dev/null; then
-         ac_cv_path_shell=$SHELL
-       fi
+      /*)
+        rm -f conftest.c
+        if ("$SHELL" -c "$ac_command") 2>/dev/null; then
+          "$SHELL" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null ||
+            ac_cv_path_shell=$SHELL
+        fi
       esac
 
       case $ac_cv_path_shell in
-      (no)
-       # Prefer shells that are more likely to be installed in the
-       # same place on all hosts of this platform.  Therefore, prefer
-       # shells in /bin and /usr/bin to shells in the installer's
-       # PATH.  Also, loop through PATH first and then through
-       # shells, since less-"nice" shells in /bin and /usr/bin are
-       # more likely to be installed than "nicer" shells elsewhere.
-       as_save_IFS=$IFS; IFS=:
-       for as_dir in /bin /usr/bin $PATH
-       do
-         IFS=$as_save_IFS
-         case $as_dir in
-         (/*)
-           for ac_base in sh bash ksh sh5; do
-             rm -f conftest.c
-             if ("$as_dir/$ac_base" -c "$ac_command") 2>/dev/null; then
-               ac_cv_path_shell=$as_dir/$ac_base
-               break
-             fi
-           done
-           case $ac_cv_path_shell in
-           (/*) break
-           esac
-         esac
-       done
-       rm -f conftest.c
+      no)
+        # Prefer shells that are more likely to be installed in the
+        # same place on all hosts of this platform.  Therefore, prefer
+        # shells in /bin and /usr/bin to shells in the installer's
+        # PATH.  Also, loop through PATH first and then through
+        # shells, since less-"nice" shells in /bin and /usr/bin are
+        # more likely to be installed than "nicer" shells elsewhere.
+        ac_break_if_good_shell=:
+        as_save_IFS=$IFS; IFS=:
+        for as_dir in /bin /usr/bin $PATH
+        do
+          IFS=$as_save_IFS
+          case $as_dir in
+          /*)
+            for ac_base in sh bash ksh sh5; do
+              rm -f conftest.c
+              if ("$as_dir/$ac_base" -c "$ac_command") 2>/dev/null; then
+                if "$as_dir/$ac_base" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null
+                then
+                  test "$ac_cv_path_shell" = no
+                else
+                  ac_break_if_good_shell=break
+                  :
+                fi && ac_cv_path_shell=$as_dir/$ac_base
+                $ac_break_if_good_shell
+              fi
+            done
+            $ac_break_if_good_shell
+          esac
+        done
+        rm -f conftest.c
       esac])
    AC_MSG_RESULT($ac_cv_path_shell)
    SHELL=$ac_cv_path_shell
@@ -78,4 +91,7 @@ AC_DEFUN([AC_PROG_SHELL],
      SHELL=/bin/sh
      AC_MSG_WARN([using $SHELL, even though it does not conform to POSIX])
    fi
+   if "$SHELL" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null; then
+     AC_MSG_WARN([using $SHELL, even though it may have file descriptor bugs])
+   fi
    AC_SUBST(SHELL)])