Filename strings sent to debug hook function

["Ivan-Assen Ivanov" <ivanassen@...>]

When a "line executed" event arrives via the debug hook function (
lua_sethook etc.), one of the fields in the lua_Debug structure is
"source", containing filename or entire string.

Are there any lifetime guarantees for this string? Is it safe to keep
only the const char *, not to strcpy the string itself, for each and
every line executed?

Best regards,
Assen