experiment (documentation will follow if ok) (HH)

source/texk/web2c/luatexdir/luatex_svnversion.h

-#define luatex_svn_revision 6391
+#define luatex_svn_revision 6392

source/texk/web2c/luatexdir/tex/commands.w

@@ -80,6 +80,7 @@ void initialize_commands(void)
     primitive_tex("predisplaypenalty", assign_int_cmd, int_base + pre_display_penalty_code, int_base);
     primitive_tex("postdisplaypenalty", assign_int_cmd, int_base + post_display_penalty_code, int_base);
     primitive_luatex("mathpenaltiesmode", assign_int_cmd, int_base + math_penalties_mode_code, int_base);
+    primitive_luatex("mathdelimitersmode", assign_int_cmd, int_base + math_delimiters_mode_code, int_base);
     primitive_tex("interlinepenalty", assign_int_cmd, int_base + inter_line_penalty_code, int_base);
     primitive_tex("doublehyphendemerits", assign_int_cmd, int_base + double_hyphen_demerits_code, int_base);
     primitive_tex("finalhyphendemerits", assign_int_cmd, int_base + final_hyphen_demerits_code, int_base);

source/texk/web2c/luatexdir/tex/dumpdata.w

@@ -23,7 +23,7 @@
 
 /* we start with 907: the sum of the values of the bytes of "don knuth" */
 
-#define FORMAT_ID (907+33)
+#define FORMAT_ID (907+34)
 #if ((FORMAT_ID>=0) && (FORMAT_ID<=256))
 #error Wrong value for FORMAT_ID.
 #endif

source/texk/web2c/luatexdir/tex/equivalents.h

@@ -297,8 +297,9 @@ the |number_regs| \.{\\dimen} registers.
 #  define pre_bin_op_penalty_code 105
 #  define pre_rel_penalty_code 106
 #  define math_penalties_mode_code 107
+#  define math_delimiters_mode_code 108
 
-#  define math_option_code (math_penalties_mode_code+1)
+#  define math_option_code (math_delimiters_mode_code+1)
 
 #  define mathoption_int_base_code (math_option_code+1)                 /* one reserve */
 #  define mathoption_int_last_code (mathoption_int_base_code+8)
@@ -657,6 +658,7 @@ extern halfword last_cs_name;
 #define pre_bin_op_penalty_par             int_par(pre_bin_op_penalty_code)
 #define pre_rel_penalty_par                int_par(pre_rel_penalty_code)
 #define math_penalties_mode_par            int_par(math_penalties_mode_code)
+#define math_delimiters_mode_par           int_par(math_delimiters_mode_code)
 #define null_delimiter_space_par           dimen_par(null_delimiter_space_code)
 #define disable_lig_par                    int_par(disable_lig_code)
 #define disable_kern_par                   int_par(disable_kern_code)

source/texk/web2c/luatexdir/tex/texmath.w

@@ -2046,9 +2046,9 @@ void math_left_right(void)
         delimiteroptions(p) = options;
         delimiterclass(p) = type;
         delimiteritalic(p) = 0;
+        delimitersamesize(p) = 0;
 
         scan_delimiter(delimiter(p), no_mathcode);
-
         if (t == no_noad_side) {
             tail_append(new_noad());
             subtype(tail) = inner_noad_type;

source/texk/web2c/luatexdir/tex/texnodes.h

@@ -485,7 +485,7 @@ typedef enum {
 #  define noadextra1(a)  vlink((a)+6) /* we need to match delimiter (saves copy) */
 #  define noadoptions(a) vinfo((a)+6)
 #  define noadextra3(a)  vlink((a)+7) /* see (!) below */
-#  define noadextra4(a)  vinfo((a)+7)
+#  define noadextra4(a)  vinfo((a)+7) /* used to store samesize */
 
 /* accent noads */
 
@@ -497,15 +497,15 @@ typedef enum {
 
 /* left and right noads */
 
-#  define fence_noad_size     8            /* needs to match noad size */
-#  define delimiteritalic(a)  vlink((a)+4)
-/* define delimiterwidth(a)   vinfo((a)+4) */
-#  define delimiterheight(a)  vlink((a)+5)
-#  define delimiterdepth(a)   vinfo((a)+5)
-#  define delimiter(a)        vlink((a)+6) /* |delimiter| field in left and right noads */
-#  define delimiteroptions(a) vinfo((a)+6)
-#  define delimiterclass(a)   vlink((a)+7) /* (!) we could probably pack some more in 6 */
-#  define delimiterextra1(a)  vinfo((a)+7) /* not used */
+#  define fence_noad_size      8            /* needs to match noad size */
+#  define delimiteritalic(a)   vlink((a)+4)
+/* define delimiterwidth(a)    vinfo((a)+4) */
+#  define delimiterheight(a)   vlink((a)+5)
+#  define delimiterdepth(a)    vinfo((a)+5)
+#  define delimiter(a)         vlink((a)+6) /* |delimiter| field in left and right noads */
+#  define delimiteroptions(a)  vinfo((a)+6)
+#  define delimiterclass(a)    vlink((a)+7) /* (!) we could probably pack some more in 6 */
+#  define delimitersamesize(a) vinfo((a)+7) /* set by engine */
 
 /* when dimensions then axis else noaxis */