From aa98c70f82a7f39ccc5662b985c078281165d10e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <tex@2krueger.de>
Date: Sun, 25 Apr 2021 18:09:13 +0200
Subject: [PATCH] Reenable amsmath

---
 luamml-amsmath.lua         |  7 +++++--
 luamml-patches-amsmath.sty |  7 ++++---
 luamml-tex.lua             | 10 +++++++++-
 luamml.sty                 |  5 ++++-
 test_tex.tex               |  1 +
 5 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/luamml-amsmath.lua b/luamml-amsmath.lua
index f25ca05..1e961c4 100644
--- a/luamml-amsmath.lua
+++ b/luamml-amsmath.lua
@@ -1,5 +1,6 @@
 local write_xml = require'luamml-xmlwriter'
 local make_root = require'luamml-convert'.make_root
+local save_result = require'luamml-tex'.save_result
 
 local properties = node.get_properties_table()
 
@@ -14,7 +15,6 @@ lua.get_functions_table()[funcid] = function()
   local props = assert(properties[startmath])
   local mml = assert(props.saved_mathml_table)
   props.saved_mathml_table = nil
-  table.insert(mml, 1, {[0] = 'maligngroup'})
   if mml[0] == 'mstyle' and mml.displaystyle == true then
     mml[0], mml.displaystyle, mml.scriptlevel = 'mtd', nil, nil
   else
@@ -68,7 +68,10 @@ lua.get_functions_table()[funcid] = function()
   local mml_table = props.mathml_table_node_table
   props.mathml_table_node_table = nil
   if not mml_table then return end
-  print(write_xml(make_root(mml_table, 0)))
+  local columns = node.count(node.id'align_record', tex.lists.align_head)//2
+  mml_table.columnalign = string.rep('right left', columns, ' ')
+  mml_table.columnalign = string.rep('0.3em', columns, '0.8em ') -- FIXME: 0.3em is a hack needed since MathML doesn't add spacing for our empty mrow
+  save_result(mml_table, 0)
 end
 
 funcid = luatexbase.new_luafunction'luamml_last_math_alignmark:'
diff --git a/luamml-patches-amsmath.sty b/luamml-patches-amsmath.sty
index 15565fe..ae74dc9 100644
--- a/luamml-patches-amsmath.sty
+++ b/luamml-patches-amsmath.sty
@@ -17,12 +17,14 @@
         \ifmeasuring@
           \luamml_flag_ignore:
         \else
-          \luamml_flag_alignment_left:
+        \luamml_flag_save:
         \fi
       $
     }
     \ifmeasuring@
       \savefieldlength@
+    \else
+      \luamml_amsmath_add_box_to_row:
     \fi
     \set@field
     \tabskip\z@skip
@@ -34,13 +36,12 @@
       \displaystyle
       {
         {}
-        \luamml_last_math_alignmark:
         ##
       }
       \ifmeasuring@
         \luamml_flag_ignore:
       \else
-        \luamml_flag_alignment_right:
+        \luamml_flag_save:
       \fi
       $
     }
diff --git a/luamml-tex.lua b/luamml-tex.lua
index 28e0c3e..175ba78 100644
--- a/luamml-tex.lua
+++ b/luamml-tex.lua
@@ -38,6 +38,10 @@ end
 local mlist_buffer
 local mlist_result
 
+local function save_result(xml, style)
+  mlist_result = write_xml(make_root(xml, style))
+end
+
 luatexbase.add_to_callback('pre_mlist_to_hlist_filter', function(mlist, style)
   local flag = tex.count.l__luamml_flag_int
   if flag & 3 == 3 then
@@ -57,7 +61,7 @@ luatexbase.add_to_callback('pre_mlist_to_hlist_filter', function(mlist, style)
   end
   local xml = process_mlist(new_mlist, style == 'display' and 0 or 2)
   if flag & 2 == 0 then
-    mlist_result = write_xml(make_root(xml, (style == 'display' or flag & 1 == 1) and 0 or 2))
+    save_result(xml, (style == 'display' or flag & 1 == 1) and 0 or 2)
   else
     assert(style == 'text')
     local startmath = tex.nest.top.tail
@@ -86,3 +90,7 @@ lua.get_functions_table()[funcid] = function()
   tex.sprint(-2, tostring(pdf.immediateobj('stream', mlist_result, '/Subtype /application#2Fmathml+xml\n' .. token.scan_argument(true))))
   mlist_result = nil
 end
+
+return {
+  save_result = save_result,
+}
diff --git a/luamml.sty b/luamml.sty
index 89dc1e5..d78d4a2 100644
--- a/luamml.sty
+++ b/luamml.sty
@@ -4,6 +4,9 @@
 \int_new:N \l__luamml_flag_int
 \lua_now:n { require'luamml-tex' }
 
+\cs_new:Nn \luamml_flag_save: {
+  \int_set:Nn \l__luamml_flag_int { 2 }
+}
 \cs_new:Nn \luamml_flag_ignore: {
   \int_set:Nn \l__luamml_flag_int { 3 }
 }
@@ -14,4 +17,4 @@
   \int_set:Nn \l__luamml_flag_int { 6 }
 }
 
-% \RequirePackage { luamml-patches-amsmath }
+\RequirePackage { luamml-patches-amsmath }
diff --git a/test_tex.tex b/test_tex.tex
index fb1e967..a6adc1b 100644
--- a/test_tex.tex
+++ b/test_tex.tex
@@ -27,6 +27,7 @@
   1+2&=3\\
   5
 \end{align}
+\ShowMathMLObj
 
 Es gilt $\sin(x)-\sin(x+2\pi)=0$.
 \end{document}