add fallback for ``node.end_of_math()``

1 files changed, 10 insertions, 0 deletions

diff --git a/luaotfload.dtx b/luaotfload.dtx
index 9ed00b5..25fd8f0 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -1496,6 +1496,16 @@ if tex.luatexversion < luatex_version then
     warning("LuaTeX v%.2f is old, v%.2f is recommended.",
              tex.luatexversion/100,
              luatex_version   /100)
+    --- we install a fallback for older versions as a safety
+    if not node.end_of_math then
+        local math_t          = node.id"math"
+        local traverse_nodes  = node.traverse_id
+        node.end_of_math = function (n)
+            for n in traverse_nodes(math_t, n.next) do
+                return n
+            end
+        end
+    end
 end
 
 %    \end{macrocode}