sync with experimental

source/texk/web2c/luatexdir/luatex_svnversion.h

 #ifndef luatex_svn_revision_h
 #define luatex_svn_revision_h
-#define luatex_svn_revision 7507
+#define luatex_svn_revision 7509
 #endif

source/texk/web2c/luatexdir/tex/mainbody.c

@@ -441,7 +441,6 @@ int main_initialize(void)
         memset(eqtb, 0, sizeof(memory_word) * (unsigned) (eqtb_top + 1));
         init_string_pool_array((unsigned) max_strings);
         reset_cur_string();
-        show_stream_par = -1;
     }
     /*tex
         Check the ``constant'' values...

source/texk/web2c/luatexdir/tex/maincontrol.c

@@ -4317,6 +4317,7 @@ void initialize(void)
         page_top_offset_par = one_inch;
         page_right_offset_par = one_inch;
         page_bottom_offset_par = one_inch;
+        show_stream_par = -1;
         ini_init_primitives();
         hash_used = frozen_control_sequence;
         hash_high = 0;