maint: update gnulib and copyright dates for 2017

[debian/gzip] / m4 / shell.m4

diff --git a/m4/shell.m4 b/m4/shell.m4
index 0d7b7e4b471845600c804a9a685f7bacf9887fb3..ff5cf1aae2efea6c94fd9362042be5a81230fbac 100644 (file)
--- a/m4/shell.m4
+++ b/m4/shell.m4
@@ -1,6 +1,6 @@
 # Check for a working shell.
 
-# Copyright (C) 2000-2001, 2007, 2009-2011 Free Software Foundation, Inc.
+# Copyright (C) 2000-2001, 2007, 2009-2017 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)
@@ -34,40 +34,53 @@ AC_DEFUN([AC_PROG_SHELL],
         # 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
+          "$SHELL" -c "$ac_maybe_solaris_sh_bug" 2>/dev/null ||
+            ac_cv_path_shell=$SHELL
         fi
       esac
 
       case $ac_cv_path_shell in
-      (no)
+      no)
         # Prefer shells that are more likely to be installed in the
         # same place on all hosts of this platform.  Therefore, prefer
         # shells in /bin and /usr/bin to shells in the installer's
         # PATH.  Also, loop through PATH first and then through
         # shells, since less-"nice" shells in /bin and /usr/bin are
         # more likely to be installed than "nicer" shells elsewhere.
+        ac_break_if_good_shell=:
         as_save_IFS=$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
-                ac_cv_path_shell=$as_dir/$ac_base
-                break
+                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
-            case $ac_cv_path_shell in
-            (/*) break
-            esac
+            $ac_break_if_good_shell
           esac
         done
         rm -f conftest.c
@@ -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)])