nonblocking: provide O_NONBLOCK for mingw

[gnulib.git] / m4 / setenv.m4

diff --git a/m4/setenv.m4 b/m4/setenv.m4
index fec4a2c..ba619b0 100644 (file)
--- a/m4/setenv.m4
+++ b/m4/setenv.m4
@@ -1,5 +1,5 @@
-# setenv.m4 serial 19
-dnl Copyright (C) 2001-2004, 2006-2010 Free Software Foundation, Inc.
+# setenv.m4 serial 21
+dnl Copyright (C) 2001-2004, 2006-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -21,7 +21,9 @@ AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
     HAVE_DECL_SETENV=0
   fi
   AC_CHECK_FUNCS_ONCE([setenv])
-  if test $ac_cv_func_setenv = yes; then
+  if test $ac_cv_func_setenv = no; then
+    HAVE_SETENV=0
+  else
     AC_CACHE_CHECK([whether setenv validates arguments],
       [gl_cv_func_setenv_works],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
@@ -57,9 +59,12 @@ AC_DEFUN([gl_FUNC_SETENV_SEPARATE],
 AC_DEFUN([gl_FUNC_UNSETENV],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_CHECK_DECLS_ONCE([unsetenv])
+  if test $ac_cv_have_decl_unsetenv = no; then
+    HAVE_DECL_UNSETENV=0
+  fi
   AC_CHECK_FUNCS([unsetenv])
   if test $ac_cv_func_unsetenv = no; then
-    HAVE_UNSETENV=0
     AC_LIBOBJ([unsetenv])
     gl_PREREQ_UNSETENV
   else
@@ -68,6 +73,8 @@ AC_DEFUN([gl_FUNC_UNSETENV],
       [AC_COMPILE_IFELSE(
          [AC_LANG_PROGRAM(
             [[
+#undef _BSD
+#define _BSD 1 /* unhide unsetenv declaration in OSF/1 5.1 <stdlib.h> */
 #include <stdlib.h>
 extern
 #ifdef __cplusplus
@@ -90,20 +97,30 @@ int unsetenv();
     fi
 
     dnl Solaris 10 unsetenv does not remove all copies of a name.
+    dnl Haiku alpha 2 unsetenv gets confused by assignment to environ.
     dnl OpenBSD 4.7 unsetenv("") does not fail.
     AC_CACHE_CHECK([whether unsetenv obeys POSIX],
       [gl_cv_func_unsetenv_works],
       [AC_RUN_IFELSE([AC_LANG_PROGRAM([[
        #include <stdlib.h>
        #include <errno.h>
+       extern char **environ;
       ]], [[
-       char entry[] = "b=2";
+       char entry1[] = "a=1";
+       char entry2[] = "b=2";
+       char *env[] = { entry1, entry2, NULL };
        if (putenv ((char *) "a=1")) return 1;
-       if (putenv (entry)) return 2;
-       entry[0] = 'a';
+       if (putenv (entry2)) return 2;
+       entry2[0] = 'a';
        unsetenv ("a");
        if (getenv ("a")) return 3;
        if (!unsetenv ("") || errno != EINVAL) return 4;
+       entry2[0] = 'b';
+       environ = env;
+       if (!getenv ("a")) return 5;
+       entry2[0] = 'a';
+       unsetenv ("a");
+       if (getenv ("a")) return 6;
       ]])],
       [gl_cv_func_unsetenv_works=yes], [gl_cv_func_unsetenv_works=no],
       [gl_cv_func_unsetenv_works="guessing no"])])