Assert that coroutine frame exists

Author: CoolCat467

src/trio/_core/_ki.py

@@ -143,6 +143,7 @@ def decorator(fn: Callable[ArgsT, RetT]) -> Callable[ArgsT, RetT]:
             def wrapper(*args: ArgsT.args, **kwargs: ArgsT.kwargs) -> RetT:  # type: ignore[misc]
                 # See the comment for regular generators below
                 coro = fn(*args, **kwargs)
+                assert coro.cr_frame is not None, "Coroutine frame should exist"
                 coro.cr_frame.f_locals[LOCALS_KEY_KI_PROTECTION_ENABLED] = enabled
                 return coro  # type: ignore[return-value]
 

src/trio/_core/_run.py

@@ -1782,6 +1782,7 @@ async def python_wrapper(orig_coro: Awaitable[RetT]) -> RetT:
                 return await orig_coro
 
             coro = python_wrapper(coro)
+        assert coro.cr_frame is not None, "Coroutine frame should exist"
         coro.cr_frame.f_locals.setdefault(LOCALS_KEY_KI_PROTECTION_ENABLED, system_task)
 
         ######