From cab73095d7d9dd76c9973688474da279a9311d63 Mon Sep 17 00:00:00 2001
From: Hironori Kitagawa <h_kitagawa2001@yahoo.co.jp>
Date: Mon, 28 Aug 2017 17:34:42 +0900
Subject: [PATCH] fix #37467 (Is it safe to write a whatsit in math mode?)

---
 src/ltj-direction.lua |  4 ++--
 src/luatexja-core.sty | 16 ++++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/ltj-direction.lua b/src/ltj-direction.lua
index 9d650f2..f26d9c5 100644
--- a/src/ltj-direction.lua
+++ b/src/ltj-direction.lua
@@ -174,7 +174,7 @@ do
       local lv = tex_nest.ptr -- must be >= 1
       if not v then
          v = get_dir_count()
-	 if abs(tex_nest[lv-1].mode) == ltjs.mmode and v == dir_tate then
+	 if abs(tex_nest[lv].mode) == ltjs.mmode and v == dir_tate then
 	    v = dir_utod
 	 end
       elseif v=='adj' then
@@ -194,7 +194,7 @@ do
       local lv = tex_nest.ptr
       if not v then
          v,name  = get_dir_count(), nil
-	 if lv>=1 and abs(tex_nest[lv-1].mode) == ltjs.mmode and v == dir_tate then
+	 if abs(tex_nest[lv].mode) == ltjs.mmode and v == dir_tate then
 	    v = dir_utod
 	 end
       elseif v=='adj' then
diff --git a/src/luatexja-core.sty b/src/luatexja-core.sty
index 3ea21ca..6a4a230 100644
--- a/src/luatexja-core.sty
+++ b/src/luatexja-core.sty
@@ -604,6 +604,8 @@
   }
   \PushPreHook{hbox}{\luafunction\ltj@@box@dirhook\aftergroup\ltj@@reset@badness}
   \PushPreHook{vbox}{\luafunction\ltj@@box@dirhook\aftergroup\ltj@@reset@badness}
+  \PushPreHook{math}{\luafunction\ltj@@box@dirhook}
+  \PushPreHook{display}{\luafunction\ltj@@box@dirhook}
 \else
   \let\ltj@@everyhbox=\everyhbox\let\ltj@@everyvbox=\everyvbox
   \newtoks\ltj@@i@everyhbox\newtoks\ltj@@i@everyvbox
@@ -618,6 +620,20 @@
     \aftergroup\ltj@@reset@badness\the\ltj@@i@everyhbox}
   \ltj@@everyvbox{\luafunction\ltj@@box@dirhook
     \aftergroup\ltj@@reset@badness\the\ltj@@i@everyvbox}
+  %% math
+  \ifltj@in@latex
+    \frozen@everymath{\luafunction\ltj@@box@dirhook\check@mathfonts\the\everymath}
+  \else
+    \let\ltj@@everymath=\everymath\newtoks\ltj@@i@everymath\let\everymath=\ltj@@i@everymath
+    \ltj@@everymath{\luafunction\ltj@@box@dirhook\the\ltj@@i@everymath}
+  \fi
+  %% display
+  \ifltj@in@latex
+    \frozen@everydisplay{\luafunction\ltj@@box@dirhook\check@mathfonts\the\everydisplay}
+  \else
+    \let\ltj@@everydisplay=\everydisplay\newtoks\ltj@@i@everydisplay\let\everydisplay=\ltj@@i@everydisplay
+    \ltj@@everydisplay{\luafunction\ltj@@box@dirhook\the\ltj@@i@everydisplay}
+  \fi
 \fi
 
 \newluafunction\ltj@@reset@badness@inner
-- 
2.11.0