Although the specific cause -- (mode_t)-1 -- is something that you can't really do in many languages. So you'd likely have to write 0777 or equivalent explicitly down, making it so much more obvious what a bad idea that is.
It's one part of a cascade of errors. The author(s) defined an opaque MODE_INVALID but wrote code depending on their 'knowledge' of its underlying value. Signed/unsigned confusion is typical of C, though.
The 'fixed' code¹ has the property that calling it to create a file with mode==0 (i.e. no permissions) actually creates one with mode==0644 (i.e. some permissions), which is a wtf r u doin that can't be blamed on C.
