Fix #29157.

diff --git a/src/ltj-pretreat.lua b/src/ltj-pretreat.lua
index ad91821..8474fb1 100644 (file)
--- a/src/ltj-pretreat.lua
+++ b/src/ltj-pretreat.lua
@@ -47,7 +47,6 @@ local function suppress_hyphenate_ja(head)
    local non_math, p = true, head
    wt = {}
    while p do
-   --for p in node_traverse(head) do
       if p.id == id_glyph then
         if (has_attr(p, attr_icflag) or 0)<=0 and ltjc_is_ucs_in_japanese_char(p) then
            p.font = has_attr(p, attr_curjfnt) or p.font
@@ -55,7 +54,8 @@ local function suppress_hyphenate_ja(head)
            set_attr(p, attr_orig_char, p.char)
         end
       elseif p.id == id_math then 
-        while p.id~=id_math do p = node_next(p) end
+        p = node_next(p) -- skip math on
+        while p and p.id~=id_math do p = node_next(p) end
       elseif p.id == id_whatsit and p.subtype==sid_user and p.user_id==30112 then
         wt[#wt+1] = p; head = node_remove(head, p)
       end