Crash setting user data text from a script

[sentry-io]

Sentry Issue: ASEPRITE-1N3

EXCEPTION_ACCESS_VIOLATION_READ / 0x0: Fatal Error: EXCEPTION_ACCESS_VIOLATION_READ / 0x0

Thread 43264 Crashed:
0   Aseprite.exe                    0x7ff69b040dd3      [inlined] std::_Narrow_char_traits<T>::length (xstring:400)
1   Aseprite.exe                    0x7ff69b040dd3      [inlined] std::basic_string<T>::{ctor} (xstring:2540)
2   Aseprite.exe                    0x7ff69b040dd3      app::script::UserData_set_text<T> (userdata.h:70)
3   Aseprite.exe                    0x7ff69b28547a      luaD_precall (ldo.c:532)
4   Aseprite.exe                    0x7ff69b28e14f      luaV_execute (lvm.c:1654)
5   Aseprite.exe                    0x7ff69b284b81      ccall (ldo.c:577)
6   Aseprite.exe                    0x7ff69b28e8ef      luaV_finishset (lvm.c:354)
7   Aseprite.exe                    0x7ff69b28c6a7      luaV_execute (lvm.c:1158)
8   Aseprite.exe                    0x7ff69b284b81      ccall (ldo.c:577)
9   Aseprite.exe                    0x7ff69b285812      luaD_rawrunprotected (ldo.c:144)
10  Aseprite.exe                    0x7ff69b28524f      luaD_pcall (ldo.c:892)
11  Aseprite.exe                    0x7ff69b28086d      lua_pcallk (lapi.c:1057)
12  Aseprite.exe                    0x7ff69adb70ae      app::script::Engine::evalCode (engine.cpp:561)
13  Aseprite.exe                    0x7ff69adb7781      app::script::Engine::evalFile (engine.cpp:629)
14  Aseprite.exe                    0x7ff69adb79d5      app::script::Engine::evalUserFile (engine.cpp:646)
15  Aseprite.exe                    0x7ff69af3de79      app::RunScriptCommand::onExecute (cmd_run_script.cpp:79)
16  Aseprite.exe                    0x7ff69ad0becc      app::Context::executeCommand (context.cpp:188)
17  Aseprite.exe                    0x7ff69ad0bfc2      app::Context::executeCommandFromMenuOrShortcut (context.cpp:157)
18  Aseprite.exe                    0x7ff69adf6041      app::CustomizedGuiManager::processKey (gui.cpp:779)
19  Aseprite.exe                    0x7ff69adf567f      app::CustomizedGuiManager::onProcessMessage (gui.cpp:586)
20  Aseprite.exe                    0x7ff69b1c1d98      ui::Manager::sendMessageToWidget (manager.cpp:2023)
21  Aseprite.exe                    0x7ff69b1c1515      ui::Manager::pumpQueue (manager.cpp:1897)
22  Aseprite.exe                    0x7ff69b1be32d      ui::Manager::dispatchMessages (manager.cpp:864)
23  Aseprite.exe                    0x7ff69b1c1c39      ui::Manager::run (manager.cpp:292)
24  Aseprite.exe                    0x7ff69ac8cbda      app::App::run (app.cpp:548)
25  Aseprite.exe                    0x7ff69ac84b5d      app_main (main.cpp:152)
26  Aseprite.exe                    0x7ff69b44d3d5      wWinMain (main.cpp:40)
27  Aseprite.exe                    0x7ff69b3c1971      [inlined] invoke_main (exe_common.inl:118)
28  Aseprite.exe                    0x7ff69b3c1971      __scrt_common_main_seh (exe_common.inl:288)
29  KERNEL32.DLL                    0x7fff55bb7343      BaseThreadInitThunk
30  ntdll.dll                       0x7fff57a626b0      RtlUserThreadStart