Prevent erroneous assignment to LL.setdtor() proxy._target field.

Trim redundant output from test_setdtor.lua.

2 files changed, 17 insertions, 15 deletions

diff --git a/indra/llcommon/lua_function.cpp b/indra/llcommon/lua_function.cpp
index 12cff89fbd..f61cf3fe10 100644
--- a/indra/llcommon/lua_function.cpp
+++ b/indra/llcommon/lua_function.cpp
@@ -1050,7 +1050,7 @@ lua_function(
     }
     // called with (desc, obj, dtor), returns proxy object
     lua_checkdelta(L, -2);
-    lluau_checkstack(L, 3);         // might get up to 6 stack entries
+//  lluau_checkstack(L, 0);         // might get up to 3 stack entries
     auto desc{ lua_tostdstring(L, 1) };
     // Get Lua "references" for each of the object and the dtor function.
     int objref = lua_ref(L, 2);
@@ -1150,6 +1150,8 @@ void setdtor_refs::push_metatable(lua_State* L)
             return (lhs._target <= rhs._target)
         end,
         __newindex = function(t, key, value)
+            assert(key ~= '_target',
+                   "Don't try to replace a setdtor() proxy's _target")
             t._target[key] = value
         end,
         __call = function(func, ...)
diff --git a/indra/newview/scripts/lua/test_setdtor.lua b/indra/newview/scripts/lua/test_setdtor.lua
index 743c5168d0..61ed86dcc8 100644
--- a/indra/newview/scripts/lua/test_setdtor.lua
+++ b/indra/newview/scripts/lua/test_setdtor.lua
@@ -7,6 +7,7 @@ print('arithmetic')
 n = LL.setdtor('arithmetic', 11, print)
 print("n =", n)
 print("n._target =", n._target)
+print(pcall(function() n._target = 12 end))
 print("getmetatable(n) =", inspect(getmetatable(n)))
 print("-n =", -n)
 for i = 10, 12 do
@@ -20,20 +21,19 @@ for i = 10, 12 do
     print(`n >= {i}`, n >= tempi)
     print(`n >  {i}`, n >  tempi)
 end
-for i = 2, 3 do
-    print(`n + {i} =`, n + i)
-    print(`{i} + n =`, i + n)
-    print(`n - {i} =`, n - i)
-    print(`{i} - n =`, i - n)
-    print(`n * {i} =`, n * i)
-    print(`{i} * n =`, i * n)
-    print(`n / {i} =`, n / i)
-    print(`{i} / n =`, i / n)
-    print(`n % {i} =`, n % i)
-    print(`{i} % n =`, i % n)
-    print(`n ^ {i} =`, n ^ i)
-    print(`{i} ^ n =`, i ^ n)
-end
+i = 2
+print(`n + {i} =`, n + i)
+print(`{i} + n =`, i + n)
+print(`n - {i} =`, n - i)
+print(`{i} - n =`, i - n)
+print(`n * {i} =`, n * i)
+print(`{i} * n =`, i * n)
+print(`n / {i} =`, n / i)
+print(`{i} / n =`, i / n)
+print(`n % {i} =`, n % i)
+print(`{i} % n =`, i % n)
+print(`n ^ {i} =`, n ^ i)
+print(`{i} ^ n =`, i ^ n)
 
 print('string')
 s = LL.setdtor('string', 'hello', print)