From 372e43e16571dc80d55e20f3fcfebf635eb01fd7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <tex@2krueger.de>
Date: Tue, 27 Apr 2021 01:47:42 +0200
Subject: [PATCH] Fix align spacing

---
 luamml-amsmath.lua | 2 +-
 luamml-convert.lua | 7 ++++++-
 test_tex.tex       | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/luamml-amsmath.lua b/luamml-amsmath.lua
index 1e961c4..e383d12 100644
--- a/luamml-amsmath.lua
+++ b/luamml-amsmath.lua
@@ -70,7 +70,7 @@ lua.get_functions_table()[funcid] = function()
   if not mml_table then return end
   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
+  mml_table.columnspacing = string.rep('0', 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
 
diff --git a/luamml-convert.lua b/luamml-convert.lua
index ab83c94..5500f9e 100644
--- a/luamml-convert.lua
+++ b/luamml-convert.lua
@@ -376,10 +376,15 @@ function nodes_to_table(head, cur_style)
     end
     nonscript = nil
     if core and new_core ~= space_like then
-      core = new_core
+      core = core == space_like and new_core or nil
     end
     mn = new_mn
   end
+  -- In TeX, groups are never space like
+  if core == space_like then
+    core = {[0] = 'mi', intent = '@ignore'}
+    result[#result+1] = core
+  end
   if t[0] == 'mrow' and #t == 1 then
     assert(t == result)
     result = t[1]
diff --git a/test_tex.tex b/test_tex.tex
index 90f3d7e..8a00fc5 100644
--- a/test_tex.tex
+++ b/test_tex.tex
@@ -25,7 +25,7 @@
 \]
 
 \begin{align}
-  abc&=def\\
+  abc&=def & e^{\mathrm{i}\pi}&=-1\\
   1+2&=3\\
   5
 \end{align}