3 files changed, 14 insertions, 8 deletions

diff --git a/src/cancel.cpp b/src/cancel.cpp
index 4f04857..a62fa96 100644
--- a/src/cancel.cpp
+++ b/src/cancel.cpp
@@ -176,17 +176,17 @@ LUAG_FUNC(thread_cancel)
     STACK_CHECK_START_REL(L_, 0);
     switch (_lane->cancel(_op, _hook_count, _until, _wake_lane)) {
     default: // should never happen unless we added a case and forgot to handle it
-        LUA_ASSERT(L_, false);
+        raise_luaL_error(L_, "should not get here!");
         break;
 
     case CancelResult::Timeout:
-        lua_pushboolean(L_, 0); // false
-        lua_pushstring(L_, "timeout"); // false "timeout"
+        lua_pushboolean(L_, 0);                                                                    // false
+        lua_pushstring(L_, "timeout");                                                             // false "timeout"
         break;
 
     case CancelResult::Cancelled:
-        lua_pushboolean(L_, 1); // true
-        std::ignore = _lane->pushThreadStatus(L_); // true status
+        lua_pushboolean(L_, 1);                                                                    // true
+        std::ignore = _lane->pushThreadStatus(L_);                                                 // true "<status>"
         break;
     }
     STACK_CHECK(L_, 2);
diff --git a/src/intercopycontext.cpp b/src/intercopycontext.cpp
index 285ca9b..34a1c95 100644
--- a/src/intercopycontext.cpp
+++ b/src/intercopycontext.cpp
@@ -913,7 +913,10 @@ LuaType InterCopyContext::processConversion() const
         // perform the custom cloning part
         lua_insert(L2, -2);                                                                        //                                                L2: ... u mt
         // __lanesclone should always exist because we wouldn't be restoring data from a userdata_clone_sentinel closure to begin with
-        std::ignore = luaG_getfield(L2, -1, "__lanesclone");                                       //                                                L2: ... u mt __lanesclone
+        LuaType const _funcType{ luaG_getfield(L2, -1, "__lanesclone") };                          //                                                L2: ... u mt __lanesclone
+        if (_funcType != LuaType::FUNCTION) {
+            raise_luaL_error(getErrL(), "INTERNAL ERROR: __lanesclone is a %s, not a function", luaG_typename(L2, _funcType).data());
+        }
         lua_remove(L2, -2);                                                                        //                                                L2: ... u __lanesclone
         lua_pushlightuserdata(L2, _clone);                                                         //                                                L2: ... u __lanesclone clone
         lua_pushlightuserdata(L2, _source);                                                        //                                                L2: ... u __lanesclone clone source
diff --git a/src/state.cpp b/src/state.cpp
index 18c5ae2..267554e 100644
--- a/src/state.cpp
+++ b/src/state.cpp
@@ -167,7 +167,7 @@ namespace state {
         DEBUGSPEW_CODE(DebugSpew(U_) << "calling on_state_create()" << std::endl);
         if (U_->onStateCreateFunc != reinterpret_cast<lua_CFunction>(InitializeOnStateCreate)) {
             // C function: recreate a closure in the new state, bypassing the lookup scheme
-            lua_pushcfunction(L_, U_->onStateCreateFunc); // on_state_create()
+            lua_pushcfunction(L_, U_->onStateCreateFunc);                                          // on_state_create()
         } else { // Lua function located in the config table, copied when we opened "lanes.core"
             if (mode_ != LookupMode::LaneBody) {
                 // if attempting to call in a keeper state, do nothing because the function doesn't exist there
@@ -177,7 +177,10 @@ namespace state {
             }
             kConfigRegKey.pushValue(L_);                                                           // L_: {}
             STACK_CHECK(L_, 1);
-            std::ignore = luaG_getfield(L_, -1, kOnStateCreate);                                   // L_: {} on_state_create()
+            LuaType const _funcType{ luaG_getfield(L_, -1, kOnStateCreate) };                      // L_: {} on_state_create()
+            if (_funcType != LuaType::FUNCTION) {
+                raise_luaL_error(L_, "INTERNAL ERROR: %s is a %s, not a function", kOnStateCreate.data(), luaG_typename(L_, _funcType).data());
+            }
             lua_remove(L_, -2);                                                                    // L_: on_state_create()
         }
         STACK_CHECK(L_, 1);