include_next fixes for Sun Studio 11 on Solaris 8

[Paul Eggert]

I had some in-hindsight-obvious typos in my recent include_next
patches, which were exposed by Sun Studio 11 on Solaris 8.  They would
also occur on other non-include_next C compilers.  I installed the
following to fix the bugs:

2007-06-23  Paul Eggert  <address@hidden>

        * m4/include_next.m4 (gl_CHECK_NEXT_HEADERS): Check some typos
        exposed by Sun Studio 11 cc on Solaris 8.

--- m4/include_next.m4  21 Jun 2007 04:39:09 -0000      1.2
+++ m4/include_next.m4  23 Jun 2007 07:17:45 -0000
@@ -1,4 +1,4 @@
-# include_next.m4 serial 2
+# include_next.m4 serial 3
 dnl Copyright (C) 2006, 2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -49,12 +49,15 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS],
   AC_FOREACH([gl_HEADER_NAME], [$1],
     [AS_VAR_PUSHDEF([gl_next_header],
                    [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME])))
-     AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
-     if test $gl_cv_have_include_next = no; then
+     if test $gl_cv_have_include_next = yes; then
+       AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
+     else
        AC_CACHE_CHECK(
         [absolute name of <]m4_quote(m4_defn([gl_HEADER_NAME]))[>],
         m4_quote(m4_defn([gl_next_header])),
-        [if test 
AS_VAR_GET([ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME]))) = yes; then
+        [AS_VAR_PUSHDEF([gl_header_exists],
+                        [ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME])))
+         if test AS_VAR_GET(gl_header_exists) = yes; then
            AC_LANG_CONFTEST(
              [AC_LANG_SOURCE(
                 [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]]
@@ -70,7 +73,10 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS],
                 p
                 q
               }'`'"'])
-         fi])
+         else
+           AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>'])
+         fi
+         AS_VAR_POPDEF([gl_header_exists])])
      fi
      AC_SUBST(
        AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))),