1 files changed, 21 insertions, 1 deletions

diff --git a/arabluatex.lua b/arabluatex.lua
index 4d135f3..11a91c3 100644
--- a/arabluatex.lua
+++ b/arabluatex.lua
@@ -34,6 +34,10 @@ local function gsub(s, patt, repl)
   return lpeg.match(patt, s)
 end
 
+-- makeatletter, makeatother
+local atletter = "\\makeatletter{}"
+local atother = "\\makeatother{}"
+
 -- some basic patterns:
 local ascii = lpeg.R("az", "AZ", "@@")
 local dblbkslash = lpeg.Cs("\\")
@@ -229,7 +233,23 @@ local function takeoutcapetc(str)
    return str
 end
 
+local function checkwrnested(str)
+   for i = 1,#outofarb do
+      str = gsub(str, dblbkslash * lpeg.Cs(lpeg.P("LR") + lpeg.P("RL")) * cmdargs,
+                 function(prefix, tag, body)
+                    body = string.sub(body, 2, -2)
+                    if string.find(body, "\\"..outofarb[i]) then
+                       return atletter.."\\al@wrong@nesting{}"..atother
+                    else
+                       -- nothing to do, so proceed.
+                    end
+      end)
+   end
+   return str
+end
+
 local function takeoutarb(str)
+   str = checkwrnested(str)
    for i = 1,#outofarb do
       str = gsub(str, dblbkslash * lpeg.Cs(outofarb[i]) * cmdargs,
                  function(prefix, tag, body)
@@ -725,7 +745,7 @@ end
 
 function processarbmarks(str)
    if not isintable(arbmarks, str) then
-      str = "\\LR{<??>}"
+      str = "\\LR{<??>}"..atletter.."\\al@wrong@mark{}"..atother
    else
       if tex.textdir == "TLT" then
          for i = 1,#arbmarks do