--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2009-05-21  Eric Blake  <ebb9@byu.net>
+            Bruno Haible  <bruno@clisp.org>
+
+	Second attempt to work around an AIX 5.3, 6.1 compiler bug with
+	include_next. Fix of 2008-11-20 commit.
+	* m4/include_next.m4 (gl_CHECK_NEXT_HEADERS): Also set
+	NEXT_AS_FIRST_DIRECTIVE_FOO_H.
+	* lib/math.in.h: Use NEXT_AS_FIRST_DIRECTIVE_MATH_H instead of
+	NEXT_MATH_H.
+	* modules/math (Makefile.am): Substitute NEXT_AS_FIRST_DIRECTIVE_MATH_H
+	instead of NEXT_MATH_H.
+
 2009-05-21  Bruno Haible  <bruno@clisp.org>
 
 	Avoid redefinition warnings for SIZE_MAX.

--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -22,7 +22,7 @@
 #endif
 
 /* The include_next requires a split double-inclusion guard.  */
-#@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_MATH_H@
+#@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_MATH_H@
 
 #ifndef _GL_MATH_H
 #define _GL_MATH_H

--- a/m4/include_next.m4
+++ b/m4/include_next.m4
@@ -1,4 +1,4 @@
-# include_next.m4 serial 12
+# include_next.m4 serial 13
 dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -104,8 +104,14 @@
 # For each arg foo.h, if #include_next works, define NEXT_FOO_H to be
 # '<foo.h>'; otherwise define it to be
 # '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
+# Also, if #include_next works as first preprocessing directive in a file,
+# define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be '<foo.h>'; otherwise define it to
+# be
+# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
 # That way, a header file with the following line:
 #	#@INCLUDE_NEXT@ @NEXT_FOO_H@
+# or
+#	#@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@
 # behaves (after sed substitution) as if it contained
 #	#include_next <foo.h>
 # even if the compiler does not support include_next.
@@ -167,5 +173,15 @@
      AC_SUBST(
        AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))),
        [AS_VAR_GET([gl_next_header])])
+     if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
+       gl_next_as_first_directive='<'gl_HEADER_NAME'>'
+     else
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
+       gl_next_as_first_directive=AS_VAR_GET([gl_next_header])
+     fi
+     AC_SUBST(
+       AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_quote(m4_defn([gl_HEADER_NAME]))),
+       [$gl_next_as_first_directive])
      AS_VAR_POPDEF([gl_next_header])])
 ])

--- a/modules/math
+++ b/modules/math
@@ -22,7 +22,7 @@
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
 	  sed -e 's|@''INCLUDE_NEXT_AS_FIRST_DIRECTIVE''@|$(INCLUDE_NEXT_AS_FIRST_DIRECTIVE)|g' \
 	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
-	      -e 's|@''NEXT_MATH_H''@|$(NEXT_MATH_H)|g' \
+	      -e 's|@''NEXT_AS_FIRST_DIRECTIVE_MATH_H''@|$(NEXT_AS_FIRST_DIRECTIVE_MATH_H)|g' \
 	      -e 's|@''GNULIB_CEILF''@|$(GNULIB_CEILF)|g' \
 	      -e 's|@''GNULIB_CEILL''@|$(GNULIB_CEILL)|g' \
 	      -e 's|@''GNULIB_FLOORF''@|$(GNULIB_FLOORF)|g' \