Fixes bootstrap with =m4-1.4.14 
retaining compatibility with previous versions

http://bugs.gentoo.org/308337

--- luatex-beta-0.50.0/source/m4/kpse-web2c.m4
+++ luatex-beta-0.50.0/source/m4/kpse-web2c.m4
@@ -20,7 +20,7 @@
                AS_HELP_STRING([--]m4_if($2, [yes], [dis], [en])[able-$1-default],
                               m4_if($2, [yes],
                                     [do not ])[run $1 if $3 missing],
-                              kpse_indent_26+2))[]dnl
+                              m4_eval(kpse_indent_26+2)))[]dnl
 AS_CASE([$enable_$1_default], [yes|no], ,
                             [enable_$1_default=$2])[]
 ]) # KPSE_WITH_MKTEX
@@ -44,7 +44,7 @@
                AS_HELP_STRING([--]m4_if($2, [yes], [dis], [en])[able-$1],
                               m4_if($2, [yes],
                                     [do not ])[compile and install $4],
-                              kpse_indent_26+2))[]dnl
+                              m4_eval(kpse_indent_26+2)))[]dnl
 AS_CASE([$enable_$1], [yes|no], ,
                     [enable_$1=$2])[]
 m4_ifval([$5], [
@@ -69,7 +69,7 @@
 [AC_ARG_ENABLE([$1win],
                AS_HELP_STRING([--enable-$1win],
                               [include $3 window support],
-                              kpse_indent_26+2))[]dnl
+                              m4_eval(kpse_indent_26+2)))[]dnl
 ]) # KPSE_WITH_MFWIN
 
 # KPSE_MFWIN_DEFINE(WINDOW, DEFINE, TEXT)
--- luatex-beta-0.50.0/source/texk/web2c/ac/web2c.ac
+++ luatex-beta-0.50.0/source/texk/web2c/ac/web2c.ac
@@ -47,7 +47,7 @@
 AC_ARG_ENABLE([mf-nowin],
               AS_HELP_STRING([--disable-mf-nowin],
                              [do not build a separate non-windows-capable METAFONT],
-                             kpse_indent_26+2))[]dnl
+                             m4_eval(kpse_indent_26+2)))[]dnl
 AC_ARG_WITH([mf-x-toolkit],
             AS_HELP_STRING([--without-mf-x-toolkit],
                            [do not use X toolkit for METAFONT]))[]dnl