Merge from gnulib: putenv: port to Solaris 10.

ChangeLog

 2013-03-13  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Merge from gnulib, incorporating:
+	2013-03-13 putenv: port to Solaris 10
 	2013-03-12 mktime: fix configure typo
 	2013-03-11 regex: port to mingw's recent addition of undeclared alarm
 	2013-03-11 putenv: avoid compilation warning on mingw

lib/putenv.c

@@ -62,7 +62,7 @@ static int
 _unsetenv (const char *name)
 {
   size_t len;
-#if !HAVE__PUTENV
+#if !HAVE_DECL__PUTENV
   char **ep;
 #endif
 
@@ -74,7 +74,7 @@ _unsetenv (const char *name)
 
   len = strlen (name);
 
-#if HAVE__PUTENV
+#if HAVE_DECL__PUTENV
   {
     int putenv_result, putenv_errno;
     char *name_ = malloc (len + 2);
@@ -127,9 +127,9 @@ putenv (char *string)
       return _unsetenv (string);
     }
 
-#if HAVE__PUTENV
+#if HAVE_DECL__PUTENV
   /* Rely on _putenv to allocate the new environment.  If other
-     parts of the application use _putenv, the !HAVE__PUTENV code
+     parts of the application use _putenv, the !HAVE_DECL__PUTENV code
      would fight over who owns the environ vector, causing a crash.  */
   if (name_end[1])
     return _putenv (string);
@@ -188,7 +188,7 @@ putenv (char *string)
       last_environ = new_environ;
       environ = new_environ;
     }
-#endif
 
   return 0;
+#endif
 }

m4/putenv.m4

-# putenv.m4 serial 19
+# putenv.m4 serial 20
 dnl Copyright (C) 2002-2013 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -52,5 +52,5 @@ AC_DEFUN([gl_FUNC_PUTENV],
 # Prerequisites of lib/putenv.c.
 AC_DEFUN([gl_PREREQ_PUTENV],
 [
-  AC_CHECK_FUNCS([_putenv])
+  AC_CHECK_DECLS([_putenv])
 ])