2023-04-15 00:22:00

32 files changed, 354 insertions, 55 deletions

diff --git a/doc/context/sources/general/manuals/luatex/luatex-nodes.tex b/doc/context/sources/general/manuals/luatex/luatex-nodes.tex
index 2453edb2d..e023d4dac 100644
--- a/doc/context/sources/general/manuals/luatex/luatex-nodes.tex
+++ b/doc/context/sources/general/manuals/luatex/luatex-nodes.tex
@@ -2391,7 +2391,7 @@ consistency. You can of course always define additional accessors using \type
 \supported {mlist_to_hlist}          \yes \nop
 \supported {new}                     \yes \yes
 \supported {next}                    \yes \nop
-\supported {prepend_prevdepth}       \nop \yes
+\supported {prepend_prevdepth}       \yes \yes
 \supported {prev}                    \yes \nop
 \supported {protect_glyphs}          \yes \yes
 \supported {protect_glyph}           \yes \yes
diff --git a/source/luametatex/source/tex/texmaincontrol.c b/source/luametatex/source/tex/texmaincontrol.c
index 6d6a2c031..c93011ad9 100644
--- a/source/luametatex/source/tex/texmaincontrol.c
+++ b/source/luametatex/source/tex/texmaincontrol.c
@@ -6309,7 +6309,8 @@ static void tex_aux_run_show_whatever(void)
 
     When we have version 2.10 released I might move the mode tests to the runners so that we get a
     smaller case cq. jump table and we might also go for mode 1 permanently. A side effect will be
-    that some commands codes will be collapsed (move and such).
+    that some commands codes will be collapsed (move and such). See older source for the two 
+    intermediate variants that were tested for a few years. 
 
 */
 
diff --git a/source/luametatex/source/tex/texmath.c b/source/luametatex/source/tex/texmath.c
index dff87b5cc..f4d962d68 100644
--- a/source/luametatex/source/tex/texmath.c
+++ b/source/luametatex/source/tex/texmath.c
@@ -2952,8 +2952,25 @@ void tex_run_math_accent(void)
                         }
                         break;
                     case 's': case 'S':
-                        if (tex_scan_mandate_keyword("source", 1)) {
-                            noad_source(accent) = tex_scan_int(0, NULL);
+                        switch (tex_scan_character("othOTH", 0, 0, 0)) {
+                            case 'o': case 'O':
+                                if (tex_scan_mandate_keyword("source", 2)) {
+                                    noad_source(accent) = tex_scan_int(0, NULL);
+                                }
+                                break;
+                            case 't': case 'T':
+                                if (tex_scan_mandate_keyword("stretch", 2)) {
+                                    noad_options(accent) |= noad_option_stretch;
+                                }
+                                break;
+                            case 'h': case 'H':
+                                if (tex_scan_mandate_keyword("shrink", 2)) {
+                                    noad_options(accent) |= noad_option_shrink;
+                                }
+                                break;
+                            default:
+                                tex_aux_show_keyword_error("source|stretch|shrink");
+                                goto DONE;
                         }
                         break;
                     case 'f': case 'F':
diff --git a/source/luametatex/source/tex/texmlist.c b/source/luametatex/source/tex/texmlist.c
index 91bb864d7..a3154df62 100644
--- a/source/luametatex/source/tex/texmlist.c
+++ b/source/luametatex/source/tex/texmlist.c
@@ -935,10 +935,12 @@ static halfword tex_aux_char_box(halfword fnt, int chr, halfword att, scaled *ic
             }
             return box; 
         }
-        if ((shrink && (whd.wd > target)) || (stretch && (whd.wd < target))) {
-            glyph_x_scale(glyph) = lround((double) glyph_x_scale(glyph) * target/whd.wd);
-            glyph_x_offset(glyph) = (whd.wd - target)/2;
-        }
+         if ((shrink && (whd.wd > target)) || (stretch && (whd.wd < target))) { // we need to keep an eye on it 
+             glyph_x_scale(glyph) = lround((double) glyph_x_scale(glyph) * target/whd.wd);
+          // glyph_x_offset(glyph) = (whd.wd - target)/2;
+             whd = tex_char_whd_from_glyph(glyph);
+             box_width(box) = whd.wd;
+         }
     }
     return box;
 }
@@ -1578,7 +1580,7 @@ static halfword tex_aux_make_delimiter(halfword target, halfword delimiter, int
                 the traditional width (which is fake width + italic) becomes less and the delta is
                 added. See (**).
             */
-          HERE:
+        HERE:
             result = tex_aux_char_box(fnt, chr, att, delta, glyph_math_delimiter_subtype, flat ? targetsize : 0, style, shrink, stretch);
             if (flat) { 
                 /* This will be done when we have a reasonable example. */
@@ -2873,7 +2875,11 @@ static int tex_aux_compute_accent_skew(halfword target, int flags, scaled *skew,
                         There is no bot_accent so let's assume that the shift also applies
                         to bottom and overlay accents.
                     */
-                    *skew = tex_char_unchecked_top_anchor_from_font(fnt, chr);
+                    if (flags & bot_accent_code) {
+                        *skew = tex_char_unchecked_bottom_anchor_from_font(fnt, chr);
+                    } else {
+                        *skew = tex_char_unchecked_top_anchor_from_font(fnt, chr);
+                    }
                     if (*skew != INT_MIN) {
                         *skew = tex_aux_math_x_size_scaled(fnt, *skew, size);
                         absolute = 1;
@@ -3073,8 +3079,7 @@ static void tex_aux_do_make_math_accent(halfword target, halfword accentfnt, hal
     }
     if (! accent) {
         /*tex Italic gets added to width for traditional fonts (no italic anyway): */
-//        accent = tex_aux_char_box(accentfnt, accentchr, attrlist, NULL, glyph_math_accent_subtype, basewidth, style, 0, 0); // usedwidth 
-        accent = tex_aux_char_box(accentfnt, accentchr, attrlist, NULL, glyph_math_accent_subtype, usedwidth, style, 0, 0); // usedwidth 
+        accent = tex_aux_char_box(accentfnt, accentchr, attrlist, NULL, glyph_math_accent_subtype, usedwidth, style, has_noad_option_stretch(target), has_noad_option_shrink(target)); // basewidth 
         found = 1; 
     }
     if (flags & top_accent_code) {
@@ -3156,7 +3161,13 @@ static void tex_aux_do_make_math_accent(halfword target, halfword accentfnt, hal
                 /*tex If the accent is extensible just take the center. */
                 anchor = tex_half_scaled(accentwidth);
             } else {
-                anchor = tex_char_unchecked_top_anchor_from_font(accentfnt, accentchr); /* no bot accent key */
+                if (flags & top_accent_code) {
+                    anchor = tex_char_unchecked_top_anchor_from_font(accentfnt, accentchr); /* no bot accent key */
+                } else if (flags & bot_accent_code) {
+                    anchor = tex_char_unchecked_bottom_anchor_from_font(accentfnt, accentchr); /* no bot accent key */
+                } else { 
+                    anchor = INT_MIN;
+                }
                 if (anchor == INT_MIN || has_noad_option_center(target)) {
                     /*tex just take the center */
                     anchor = tex_half_scaled(accentwidth);
diff --git a/source/luametatex/source/tex/texnodes.c b/source/luametatex/source/tex/texnodes.c
index 49a5b8fa7..63cf9e4c3 100644
--- a/source/luametatex/source/tex/texnodes.c
+++ b/source/luametatex/source/tex/texnodes.c
@@ -779,9 +779,11 @@ void lmt_nodelib_initialize(void) {
     properties, we create a new table and give it the original one as a metatable. After some
     experiments (that also included timing) with these scenarios I decided that a deep copy made no
     sense, nor did nilling. In the end both the shallow copy and the metatable variant were both
-    ok, although the second ons is slower. The most important aspect to keep in mind is that
-    references to other nodes in properties no longer can be valid for that copy. We could use two
-    tables (one unique and one shared) or metatables but that only complicates matters.
+    okay, although the metatables at that time performed a bit less. The most important aspect to 
+    keep in mind is that references to other nodes in properties no longer can be valid for that 
+    copy. We could use two tables (one unique and one shared) or metatables but that only 
+    complicates matters. Maybe some day I will remove the method that not used in \CONTEXT, just 
+    because switching methods during a run will for sure break things. 
 
     When defining a new node, we could already allocate a table but it is rather easy to do that at
     the lua end e.g. using a metatable __index method. That way it is under macro package control.
diff --git a/tex/context/base/mkii/cont-new.mkii b/tex/context/base/mkii/cont-new.mkii
index 9a1ca833a..37528b541 100644
--- a/tex/context/base/mkii/cont-new.mkii
+++ b/tex/context/base/mkii/cont-new.mkii
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2023.04.11 22:45}
+\newcontextversion{2023.04.15 00:19}
 
 %D This file is loaded at runtime, thereby providing an
 %D excellent place for hacks, patches, extensions and new
diff --git a/tex/context/base/mkii/context.mkii b/tex/context/base/mkii/context.mkii
index 994439fa2..6996d0e72 100644
--- a/tex/context/base/mkii/context.mkii
+++ b/tex/context/base/mkii/context.mkii
@@ -20,7 +20,7 @@
 %D your styles an modules.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2023.04.11 22:45}
+\edef\contextversion{2023.04.15 00:19}
 
 %D For those who want to use this:
 
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index c7c28fc7c..0623da6c5 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2023.04.11 22:45}
+\newcontextversion{2023.04.15 00:19}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index aee10b279..78fbb2605 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -49,7 +49,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2023.04.11 22:45}
+\edef\contextversion{2023.04.15 00:19}
 
 %D Kind of special:
 
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index 074d13f5d..3c36f07cf 100644
--- a/tex/context/base/mkiv/status-files.pdf
+++ b/tex/context/base/mkiv/status-files.pdf
diff --git a/tex/context/base/mkiv/status-lua.pdf b/tex/context/base/mkiv/status-lua.pdf
index e08a49d4e..12f91518e 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkxl/cont-new.mkxl b/tex/context/base/mkxl/cont-new.mkxl
index 9f4678349..cc8a43777 100644
--- a/tex/context/base/mkxl/cont-new.mkxl
+++ b/tex/context/base/mkxl/cont-new.mkxl
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2023.04.11 22:45}
+\newcontextversion{2023.04.15 00:19}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkxl/context.mkxl b/tex/context/base/mkxl/context.mkxl
index 19cc4ee85..d866f4b94 100644
--- a/tex/context/base/mkxl/context.mkxl
+++ b/tex/context/base/mkxl/context.mkxl
@@ -29,7 +29,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \immutable\edef\contextformat {\jobname}
-\immutable\edef\contextversion{2023.04.11 22:45}
+\immutable\edef\contextversion{2023.04.15 00:19}
 
 %overloadmode 1 % check frozen / warning
 %overloadmode 2 % check frozen / error
diff --git a/tex/context/base/mkxl/math-act.lmt b/tex/context/base/mkxl/math-act.lmt
index e8310ef2b..f6fd5dab5 100644
--- a/tex/context/base/mkxl/math-act.lmt
+++ b/tex/context/base/mkxl/math-act.lmt
@@ -1309,6 +1309,7 @@ do
                             else
                                 c.width = width
                             end
+c.bottomanchor = width/2 -- maybe optional
                         end
                         if italic then
                             c.italic = nil
@@ -1349,8 +1350,9 @@ do
                     end
                 end
             end
-            return
-        elseif not list or list == "all" or list == true or parameters.all then
+            goto done
+        end
+        if not list or list == "all" or list == true or parameters.all then
             list = sortedkeys(targetcharacters)
         elseif type(list) == "string" then
             list = { list }
@@ -1377,6 +1379,7 @@ do
                 end
             end
         end
+       ::done::
         feedback_tweak(whatever,target,original,done)
     end
 
@@ -1958,7 +1961,7 @@ do
         newprivateslot("minus rule right piece"),
     }
 
-    local function useminus(target,unicode,characters,parameters,skipfirst,what)
+    local function useminus(target,unicode,characters,parameters,skipfirst,what,tounicode)
         local minus   = characters[0x2212]
         local parts   = minus.parts
         if parameters == true then
@@ -1996,7 +1999,7 @@ do
                         leftcommand[xshift],
                         downcommand[yshift],
 --                         slotcommand[0][glyph],
-                    { "slot", 0, glyph, xscale, yscale },
+                        { "slot", 0, glyph, xscale, yscale },
                     },
                 }
                 part.glyph   = what[i]
@@ -2011,7 +2014,7 @@ do
 --                     slotcommand[0][0x2212],
                     { "slot", 0, 0x2212, xscale, yscale },
                 },
-                unicode          = unicode,
+                unicode          = tounicode or unicode,
                 parts            = parts,
                 partsorientation = "horizontal",
             }
@@ -2020,7 +2023,7 @@ do
 
     -- add minus parts of not there and create clipped clone
 
-    local function checkminus(target,unicode,characters,parameters,skipfirst,what)
+    local function checkminus(target,unicode,characters,parameters,skipfirst,what,tounicode)
         local minus = characters[unicode]
         local parts = minus.parts
         if parameters == true then
@@ -2092,6 +2095,7 @@ do
             }
             minus.partsorientation = "horizontal"
         end
+        minus.unicode = tounicode or unicode
     end
 
     function mathtweaks.replacerules(target,original,parameters)
@@ -2104,10 +2108,10 @@ do
             checkminus(target,0x2212,characters,minus,false,mrp)
         end
         if fraction then
-            useminus(target,fbe,characters,fraction,false,frp)
+            useminus(target,fbe,characters,fraction,false,frp,0x2044) -- division slash
         end
         if radical then
-            useminus(target,rbe,characters,radical,true,rrp)
+            useminus(target,rbe,characters,radical,true,rrp,0x2061)   -- apply function
         end
         if stacker then
             useminus(target,0x203E,characters,stacker,false,frp)
@@ -2666,6 +2670,7 @@ do -- see pagella for an extensive example
         [0x030A] = { 0x02DA, false },
         [0x0303] = { 0x02DC, true  },
         [0x20DB] = { 0x20DB, false },
+-- [0x20EF] = { 0x20EF, false },
     }
 
     datasets.fixaccents     = mapping
@@ -2673,6 +2678,18 @@ do -- see pagella for an extensive example
     datasets.flattenaccents = mapping
     datasets.copyaccents    = mapping
 
+    -- local flat = stretchingdata.flataccent
+    -- if flat then
+    --     -- Nasty! xoffset needed. Check this when we patch vf.
+    --     local flatdata = characters[flat]
+    --     flatdata.width     = width
+    --     flatdata.advance   = 0
+    --     flatdata.topanchor = topanchor
+    --     flatdata.xoffset   = width + topanchor
+    -- end
+
+local cdata = characters.data
+
     function mathtweaks.fixaccents(target,original,parameters)
         local characters = target.characters
         local done       = false
@@ -2680,22 +2697,27 @@ do -- see pagella for an extensive example
             local alias  = entry[1]
             local stretchingdata = characters[stretching]
             if stretchingdata and stretchingdata.width == 0 then
+if false then
+    local b = target.descriptions[stretching].boundingbox
+    if b then
+        local llx = b[1] * target.parameters.hfactor
+        local urx = b[3] * target.parameters.hfactor
+        width = urx - llx
+        stretchingdata.width        = width
+        stretchingdata.xoffset      = - llx
+        stretchingdata.advance      = urx
+        stretchingdata.topanchor    = width/2
+        stretchingdata.bottomanchor = width/2
+    end
+else
                 local topanchor = stretchingdata.topanchor or 0
                 local width     = -topanchor
-                      topanchor = width/2
+                topanchor = width/2
                 stretchingdata.width     = width
                 stretchingdata.advance   = 0
                 stretchingdata.topanchor = topanchor
                 stretchingdata.commands  = { rightcommand[width + topanchor], charcommand[stretching] }
--- local flat = stretchingdata.flataccent
--- if flat then
---     -- Nasty! xoffset needed. Check this when we patch vf.
---     local flatdata = characters[flat]
---     flatdata.width     = width
---     flatdata.advance   = 0
---     flatdata.topanchor = topanchor
---     flatdata.xoffset   = width + topanchor
--- end
+end
                 if not trace_tweaking then
                     done = true
                 elseif done then
@@ -2708,6 +2730,40 @@ do -- see pagella for an extensive example
         feedback_tweak("fixaccents",target,original,done)
     end
 
+    function mathtweaks.checkaccents(target,original,parameters)
+        local characters = target.characters
+        local done       = false
+        local factor     = target.parameters.hfactor
+        for unicode, data in sortedhash(characters) do
+            local width = data.width
+            if width == 0 then
+                local d = chardata[data.unicode or unicode]
+                local c = d and d.category
+                if c == "mn" then
+                    local b = target.descriptions[unicode].boundingbox
+                    if b then
+                        local llx = b[1] * factor
+                        local urx = b[3] * factor
+                        width = urx - llx
+                        data.width        = width
+                        data.xoffset      = - llx
+                        data.advance      = urx
+                        data.topanchor    = width/2
+                        data.bottomanchor = width/2
+                    end
+                    if not trace_tweaking then
+                        done = true
+                    elseif done then
+                        done[unicode] = true
+                    else
+                        done = { [unicode] = true }
+                    end
+                end
+            end
+        end
+        feedback_tweak("checkaccents",target,original,done)
+    end
+
     -- all  true|number  false
 
     function mathtweaks.extendaccents(target,original,parameters)
diff --git a/tex/context/base/mkxl/tabl-com.mkxl b/tex/context/base/mkxl/tabl-com.mkxl
index d8eb7ada7..8621d2f62 100644
--- a/tex/context/base/mkxl/tabl-com.mkxl
+++ b/tex/context/base/mkxl/tabl-com.mkxl
@@ -49,6 +49,7 @@
 \permanent\protected\lettonothing\BH
 \permanent\protected\lettonothing\BL
 \permanent\protected\lettonothing\BR
+\permanent\protected\lettonothing\BT
 \permanent\protected\lettonothing\CC
 \permanent\protected\lettonothing\CL
 \permanent\protected\lettonothing\CM
@@ -68,6 +69,8 @@
 \permanent\protected\lettonothing\HL
 \permanent\protected\lettonothing\HQ
 \permanent\protected\lettonothing\HR
+\permanent\protected\lettonothing\HF
+\permanent\protected\lettonothing\HLHL
 \permanent\protected\lettonothing\LB
 \permanent\protected\lettonothing\LC
 \permanent\protected\lettonothing\LT
@@ -94,9 +97,13 @@
 \permanent\protected\lettonothing\SM
 \permanent\protected\lettonothing\SR
 \permanent\protected\lettonothing\TB
+\permanent\protected\lettonothing\TC
 \permanent\protected\lettonothing\TL
+\permanent\protected\lettonothing\TM
 \permanent\protected\lettonothing\TR
+\permanent\protected\lettonothing\TT
 \permanent\protected\lettonothing\VL
+\permanent\protected\lettonothing\VLVL
 \permanent\protected\lettonothing\VC
 \permanent\protected\lettonothing\VD
 \permanent\protected\lettonothing\VN
diff --git a/tex/context/fonts/mkiv/bonum-math.lfg b/tex/context/fonts/mkiv/bonum-math.lfg
index 2852c6449..ce36da352 100644
--- a/tex/context/fonts/mkiv/bonum-math.lfg
+++ b/tex/context/fonts/mkiv/bonum-math.lfg
@@ -71,6 +71,9 @@ return {
                 presets.wipeanchors          { },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     -- We need to check these, are the tweaks necessary or not?
                     tweak = "dimensions",
                     list  = {
diff --git a/tex/context/fonts/mkiv/common-math-jmn.lfg b/tex/context/fonts/mkiv/common-math-jmn.lfg
index 1ebb7db39..995da0db6 100644
--- a/tex/context/fonts/mkiv/common-math-jmn.lfg
+++ b/tex/context/fonts/mkiv/common-math-jmn.lfg
@@ -1,3 +1,15 @@
+local nps = fonts.helpers.newprivateslot
+
+local fake20D6 = nps("arrow fake 0x20D6")
+local fake20D7 = nps("arrow fake 0x20D7")
+local fake20E1 = nps("arrow fake 0x20E1")
+
+local fake20EE = nps("arrow fake 0x20EE")
+local fake20EF = nps("arrow fake 0x20EF")
+local fake034D = nps("arrow fake 0x034D")
+
+local real034D = nps("arrow real 0x034D")
+
 return {
     name = "common-math-jmn",
     version = "1.00",
@@ -118,7 +130,7 @@ return {
                     builders.horibar(main,0x203E,false,false,false,0x02212)
                 end
 
-                local ffactor = antykwa and 1 or 1
+                local ffactor = antykwa and 1 or 1   -- check MS
                 local mfactor = antykwa and 1 or .8
                 local lfactor = antykwa and 1 or .8
 
@@ -131,8 +143,11 @@ return {
                 builders.extension(main,0x27F9,dfl,dfm,dar,ffactor,mfactor,lfactor)
                 builders.extension(main,0x27FA,dal,dfm,dar,ffactor,mfactor,lfactor)
 
-                local tfactor = antykwa and -0.8 or -0.8
-                local bfactor = antykwa and  0.1  or  0.1
+                local tfactor = antykwa and -0.8 or -1.1  -- move up check MS
+                local bfactor = antykwa and  0.1 or  0.2
+
+local tfactor = antykwa and -0.6 or -.6  -- move up check MS
+local bfactor = antykwa and  0.1 or  0.2
 
                 local left  = characters[0x27F5]
                 local right = characters[0x27F6]
@@ -141,17 +156,82 @@ return {
                 local height = max(left.height or 0,right.height or 0,both.height or 0)
                 local depth  = max(left.depth  or 0,right.depth  or 0,both.depth  or 0)
 
-                left .height = height  left .depth = depth
-                right.height = height  right.depth = depth
-                both .height = height  both .depth = depth
+                left .height = height ; left .depth = depth
+                right.height = height ; right.depth = depth
+                both .height = height ; both .depth = depth
+
+                -- top and bottom arrows : a real mess but now we're drawn into patching it; why are these
+                -- small ones shifted in the bbox; we could do a better job on top and bottom anchors; we
+                -- also could use the bbox as in opentype (\wideoverleftarrow etc)
+
+                local rightarrow  = characters[0x20D7]
+                local leftarrow   = copytable(rightarrow)
+                local doublearrow = copytable(rightarrow)
+                local width       = rightarrow.width
+                local height      = rightarrow.height
+
+                -- top
+
+                characters[0x20D6] = leftarrow
+                characters[0x20E1] = doublearrow
+
+                rightarrow.xoffset = -.2*width
+                leftarrow.commands = {
+                    { "offset", width, 0, 0x20D7, -1, 1 }
+                }
+                doublearrow.commands = {
+                    { "offset", antykwa and .9*width or width, 0, 0x20D7, -1, 1 },
+                    { "offset", antykwa and .1*width or     0, 0, 0x20D7,  1, 1 }
+                }
+
+                -- bottom
+
+                local rightarrow  = copytable(rightarrow)
+                local leftarrow   = copytable(leftarrow)
+                local doublearrow = copytable(doublearrow)
+
+                characters[0x20EE] = leftarrow
+                characters[0x20EF] = rightarrow
+                characters[0x034D] = doublearrow
+
+                local bheight =  .40*height -- can be tuned to match top
+                local yoffset = -.65*height -- can be tuned to match top
+
+                leftarrow  .height = bheight
+                rightarrow .height = bheight
+                doublearrow.height = bheight
+
+                rightarrow .yoffset = yoffset
+                leftarrow  .yoffset = yoffset
+                doublearrow.yoffset = yoffset
+
+                leftarrow.commands = {
+                    { "offset", width, 0, 0x20D7, -1, 1 }
+                }
+                doublearrow.commands = {
+                    { "offset", antykwa and .9*width or width, 0, 0x20D7, -1, 1 },
+                    { "offset", antykwa and .1*width or     0, 0, 0x20D7,  1, 1 }
+                }
+
+                -- extensibles
+
+                local tl = copytable(left)  ; characters[fake20D6] = tl ; characters[0x20D6].next = fake20D6 -- over
+                local tm = copytable(right) ; characters[fake20D7] = tm ; characters[0x20D7].next = fake20D7
+                local tr = copytable(both)  ; characters[fake20E1] = tr ; characters[0x20E1].next = fake20E1
+
+                tl.inneryoffset = tfactor*height ; tl.innerlocation = "top" ; tl.next = nil ; tl.italic = nil
+                tm.inneryoffset = tfactor*height ; tm.innerlocation = "top" ; tm.next = nil ; tm.italic = nil
+                tr.inneryoffset = tfactor*height ; tr.innerlocation = "top" ; tr.next = nil ; tr.italic = nil
+
+                local bl = copytable(left)  ; characters[fake20EE] = bl ; characters[0x20EE].next = fake20EE -- under
+                local bm = copytable(right) ; characters[fake20EF] = bm ; characters[0x20EF].next = fake20EF
+                local br = copytable(both)  ; characters[fake034D] = br ; characters[0x034D].next = fake034D
 
-                local t = copytable(left)  characters[0x20D6] = t t.inneryoffset = tfactor*height t.innerlocation = "top"    t.next = nil t.italic = nil -- over
-                local t = copytable(right) characters[0x20D7] = t t.inneryoffset = tfactor*height t.innerlocation = "top"    t.next = nil t.italic = nil
-                local t = copytable(both)  characters[0x20E1] = t t.inneryoffset = tfactor*height t.innerlocation = "top"    t.next = nil t.italic = nil
+                bl.inneryoffset = bfactor*height bl.innerlocation = "bottom" ; bl.next = nil ; bl.italic = nil
+                bm.inneryoffset = bfactor*height bm.innerlocation = "bottom" ; bm.next = nil ; bm.italic = nil
+                br.inneryoffset = bfactor*height br.innerlocation = "bottom" ; br.next = nil ; br.italic = nil
 
-                local t = copytable(left)  characters[0x20EE] = t t.inneryoffset = bfactor*height t.innerlocation = "bottom" t.next = nil t.italic = nil -- under
-                local t = copytable(right) characters[0x20EF] = t t.inneryoffset = bfactor*height t.innerlocation = "bottom" t.next = nil t.italic = nil
-                local t = copytable(both)  characters[0x034D] = t t.inneryoffset = bfactor*height t.innerlocation = "bottom" t.next = nil t.italic = nil
+                --
 
                 local tfactor = antykwa and -15 or -15
                 local bfactor = antykwa and   1 or   1
diff --git a/tex/context/fonts/mkiv/concrete-math.lfg b/tex/context/fonts/mkiv/concrete-math.lfg
index 142778015..e92bb122a 100644
--- a/tex/context/fonts/mkiv/concrete-math.lfg
+++ b/tex/context/fonts/mkiv/concrete-math.lfg
@@ -35,6 +35,9 @@ return {
                 presets.moveintegrals        { factor = 1.5 },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x002F] = { topleft = -0.2, bottomright = -0.2 },
diff --git a/tex/context/fonts/mkiv/dejavu-math.lfg b/tex/context/fonts/mkiv/dejavu-math.lfg
index c97765122..4098a32d0 100644
--- a/tex/context/fonts/mkiv/dejavu-math.lfg
+++ b/tex/context/fonts/mkiv/dejavu-math.lfg
@@ -57,6 +57,9 @@ return {
                 -- because once the advance is set the move is blocked and the ic stil wiped. So,
                 -- we kern. Actually the upright (ascii) f has italic correction.
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x1D453] = { bottomright = -.2 },
diff --git a/tex/context/fonts/mkiv/ebgaramond-math.lfg b/tex/context/fonts/mkiv/ebgaramond-math.lfg
index d2ef73f55..c25147b14 100644
--- a/tex/context/fonts/mkiv/ebgaramond-math.lfg
+++ b/tex/context/fonts/mkiv/ebgaramond-math.lfg
@@ -51,6 +51,9 @@ return {
                 presets.moveintegrals        { factor  = 1.5  },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "simplifykerns",
                 },
                 {
diff --git a/tex/context/fonts/mkiv/erewhon-math.lfg b/tex/context/fonts/mkiv/erewhon-math.lfg
index 223927184..5a28735f1 100644
--- a/tex/context/fonts/mkiv/erewhon-math.lfg
+++ b/tex/context/fonts/mkiv/erewhon-math.lfg
@@ -53,6 +53,9 @@ return {
                 presets.moveintegrals        { factor = 1.5 },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x002F]                = { topleft  = -0.15, bottomright = -0.15 },
diff --git a/tex/context/fonts/mkiv/kpfonts-math.lfg b/tex/context/fonts/mkiv/kpfonts-math.lfg
index 1b2eea45f..db3e44be8 100644
--- a/tex/context/fonts/mkiv/kpfonts-math.lfg
+++ b/tex/context/fonts/mkiv/kpfonts-math.lfg
@@ -26,6 +26,9 @@ return {
                     expected = "Version 0.40",
                 },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "dimensions",
                     list  = {
                         [0x2A3F] = { factor = 0.84625 }
diff --git a/tex/context/fonts/mkiv/modern-math.lfg b/tex/context/fonts/mkiv/modern-math.lfg
index fb9c8fd4b..fa4216263 100644
--- a/tex/context/fonts/mkiv/modern-math.lfg
+++ b/tex/context/fonts/mkiv/modern-math.lfg
@@ -56,6 +56,9 @@ return {
                 presets.wipeanchors          { },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "dimensions",
                     list  = {
                         [0x1D487] = { anchor = 0.9  }, -- bold italic f
diff --git a/tex/context/fonts/mkiv/newcomputermodern-math.lfg b/tex/context/fonts/mkiv/newcomputermodern-math.lfg
index 9e5e6ab3a..d147e787e 100644
--- a/tex/context/fonts/mkiv/newcomputermodern-math.lfg
+++ b/tex/context/fonts/mkiv/newcomputermodern-math.lfg
@@ -108,6 +108,9 @@ return {
                 presets.wipeanchors          { },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x0002F] = { topleft = -0.2, bottomright = -0.2 }, -- solidus
diff --git a/tex/context/fonts/mkiv/pagella-math.lfg b/tex/context/fonts/mkiv/pagella-math.lfg
index a9b3ea4bb..3aa3ef24b 100644
--- a/tex/context/fonts/mkiv/pagella-math.lfg
+++ b/tex/context/fonts/mkiv/pagella-math.lfg
@@ -83,6 +83,9 @@ return {
                 presets.wipeanchors          { },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak   = "parameters",
                     feature = "euleroverpagella",
                     list    = {
diff --git a/tex/context/fonts/mkiv/schola-math.lfg b/tex/context/fonts/mkiv/schola-math.lfg
index 58eb1a6ea..f0155cb57 100644
--- a/tex/context/fonts/mkiv/schola-math.lfg
+++ b/tex/context/fonts/mkiv/schola-math.lfg
@@ -47,6 +47,9 @@ return {
                 presets.moveintegrals        { },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x002F]                = { topleft  = -0.2,  bottomright = -0.2  },
diff --git a/tex/context/fonts/mkiv/stixtwo-math.lfg b/tex/context/fonts/mkiv/stixtwo-math.lfg
index ebacf7a81..bbe4e3685 100644
--- a/tex/context/fonts/mkiv/stixtwo-math.lfg
+++ b/tex/context/fonts/mkiv/stixtwo-math.lfg
@@ -99,6 +99,19 @@ return {
                 presets.moveintegrals         { },
                 presets.wipeitalics           { },
                 {
+                    tweak = "checkaccents",
+                },
+                -- Extensibles use .s1 (variant 1), so we cannot wipe all
+                {
+                    tweak = "wipevariants",
+                    list = {
+                        [0x20D6] = 3,
+                        [0x20D7] = 3,
+                        [0x20EE] = 3,
+                        [0x20EF] = 3,
+                    },
+                },
+                {
                     tweak = "simplifykerns",
                 },
                 {
diff --git a/tex/context/fonts/mkiv/termes-math.lfg b/tex/context/fonts/mkiv/termes-math.lfg
index 504249878..c74228179 100644
--- a/tex/context/fonts/mkiv/termes-math.lfg
+++ b/tex/context/fonts/mkiv/termes-math.lfg
@@ -49,6 +49,9 @@ return {
                 presets.moveintegrals        { factor  = 1.5  },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x002F]                = { topleft  = -0.2,  bottomright = -0.2  },
diff --git a/tex/context/fonts/mkiv/xcharter-math.lfg b/tex/context/fonts/mkiv/xcharter-math.lfg
index e2ed3e116..48b1cad5d 100644
--- a/tex/context/fonts/mkiv/xcharter-math.lfg
+++ b/tex/context/fonts/mkiv/xcharter-math.lfg
@@ -39,6 +39,9 @@ return {
                 presets.moveintegrals        { factor = 1.5 },
                 presets.wipeitalics          { },
                 {
+                    tweak = "checkaccents",
+                },
+                {
                     tweak = "kerns",
                     list  = {
                         [0x002F]                = { topleft  = -0.15, bottomright = -0.15 },
diff --git a/tex/context/modules/mkxl/s-system-macros.mkxl b/tex/context/modules/mkxl/s-system-macros.mkxl
index 605859000..7e78b265a 100644
--- a/tex/context/modules/mkxl/s-system-macros.mkxl
+++ b/tex/context/modules/mkxl/s-system-macros.mkxl
@@ -48,6 +48,8 @@
   [A4,landscape]
   [A4,landscape]
 
+\bitwiseflip \normalizelinemode \discardzerotabskipsnormalizecode
+
 \starttext
 
 \startluacode
@@ -137,7 +139,7 @@
 
         local function show(visible, check)
          -- context.starttabulate { "|l|l|l|lj2|l|l|l|l|l|l|l|l|" }
-            context.starttabulate { "|l|l|l|lj2|l|l|l|l|l|l|l|l|" }
+            context.starttabulate { "|l|l|l|lj2|l|l|l|l|l|l|l|l|l|" }
             for i=1,#list do
                 local k = list[i]
                 if check(k) then
@@ -148,6 +150,7 @@
                     local permanent  = v.permanent  and "permanent"
                     local primitive  = v.primitive  and "primitive"
                     local instance   = v.instance   and "instance"
+                    local constant   = v.constant   and "constant"
                     local dealtwith  = mutable or immutable or mutable or frozen or permanent or primitive -- beware: we can have combinations
                     local whatever   = find(k,"^[a-z][a-z][a-z]+_")
                     local cscommand  = gsub(v.cmdname or "","_"," ")
@@ -165,7 +168,7 @@
                         ctx_NC() if primitive  then ctx_bold(csname)    else
                                                     ctx_verb(csname)    end
                         ctx_NC() if parameters then context(parameters > 0 and parameters or "-") end
-                        ctx_NC() if undefined  then context.red(false) end
+                        ctx_NC() if undefined  then context.red(false)  end
                                                     context(cscommand)
                         ctx_NC() if primitive  then context(primitive)  end
                         ctx_NC() if permanent  then context(permanent)  end
@@ -174,6 +177,7 @@
                         ctx_NC() if mutable    then context(mutable)    end
                         ctx_NC() if instance   then context(instance)   end
                         ctx_NC() if noaligned  then context(noaligned)  end
+                        ctx_NC() if constant   then context(constant)   end
                         ctx_NC() if filename   then context(hashnames[filename]) end
                         ctx_NC() ctx_NR()
                     end
diff --git a/tex/context/modules/mkxl/s-text-tests.mkxl b/tex/context/modules/mkxl/s-text-tests.mkxl
new file mode 100644
index 000000000..6766a7a09
--- /dev/null
+++ b/tex/context/modules/mkxl/s-text-tests.mkxl
@@ -0,0 +1,72 @@
+%D \module
+%D   [      file=s-text-tests.mkxl,
+%D        version=2023.04.11,
+%D          title=\CONTEXT\ Style File,
+%D       subtitle=Some Text Tests,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+\continueifinputfile{s-text-tests.mkxl}
+
+%D Here we collect some tests that later will become proper macros.
+
+\usebodyfont[bonum]
+\usebodyfont[cambria]
+\usebodyfont[concrete]
+\usebodyfont[dejavu]
+\usebodyfont[ebgaramond]
+\usebodyfont[erewhon]
+\usebodyfont[kpfonts]
+\usebodyfont[libertinus]
+\usebodyfont[lucida]
+\usebodyfont[minion]
+\usebodyfont[modern]
+\usebodyfont[newcomputermodern-book]
+\usebodyfont[pagella]
+\usebodyfont[schola]
+\usebodyfont[stixtwo]
+\usebodyfont[termes]
+\usebodyfont[xcharter]
+
+\starttext
+
+\startbuffer
+(a) (f) [f] \{f\} f: f; f! f? f\textbar f* f@ f& f/ f\textbackslash
+\stopbuffer
+
+\starttexdefinition ugly #1
+    \startsubject[title=#1]
+        \start
+            \switchtobodyfont[#1]
+            {\tf \getbuffer}\blank[small]
+            {\bf \getbuffer}\blank[small]
+            {\it \getbuffer}\blank[small]
+            {\bi \getbuffer}\blank[big]
+        \stop
+    \stopsubject
+\stoptexdefinition
+
+\ugly{bonum}
+\ugly{cambria}
+\ugly{concrete}
+\ugly{dejavu}
+\ugly{ebgaramond}
+\ugly{erewhon}
+\ugly{kpfonts}
+\ugly{libertinus}
+\ugly{lucida}
+\ugly{minion}
+\ugly{modern}
+\ugly{newcomputermodern-book}
+\ugly{pagella}
+\ugly{schola}
+\ugly{stixtwo}
+\ugly{termes}
+\ugly{xcharter}
+
+\stoptext
diff --git a/tex/generic/context/luatex/luatex-fonts-merged.lua b/tex/generic/context/luatex/luatex-fonts-merged.lua
index 2e71a19d3..3cd7aa0da 100644
--- a/tex/generic/context/luatex/luatex-fonts-merged.lua
+++ b/tex/generic/context/luatex/luatex-fonts-merged.lua
@@ -1,6 +1,6 @@
 -- merged file : c:/data/develop/context/sources/luatex-fonts-merged.lua
 -- parent file : c:/data/develop/context/sources/luatex-fonts.lua
--- merge date  : 2023-04-11 22:45
+-- merge date  : 2023-04-15 00:19
 
 do -- begin closure to overcome local limits and interference