tup aborts on nested lua file error #504
Description
The attached project makes tup abort.
$ ../tup-v0.8/tup
[ tup ] [0.000s] Scanning filesystem...
[ tup ] [0.000s] Reading in new environment variables...
[ tup ] [0.000s] Parsing Tupfiles...
2) [0.001s] .
[ ] 33%tup: luaparser.c:852: parse_lua_tupfile: Assertion `lua_gettop(gls) == 0' failed.
Aborted (core dumped)
It seems to me that parse_lua_tupfile() is invoked recursively and thus the assert should compare with what lua_gettop() would return at start of parse_lua_tupfile() instead of 0