Re: [GNU-linux-libre] youtube-dl might be running non-free software from

[Adonay Felipe Nogueira]

It's been a long time since I last programmed in Lua (one of many
languages used by VLC). I know from my limited knowlege on Lua
programming that `()`, `dofile()`, `load()` (older version of
`loadstring()`), `loadfile()` and `loadstring()` can run arbitrary code
in some situations. I also know that `loadfile()` and `loadstring()`
read file and string, respectivelly. But these are only compiled, not
immediatelly run/defined. I had a look at the "youtube.lua" playlist
module, and as far as my blindness allows me to tell, I didn't see it
compiling and executing JS code as Lua code (either through `()`,
`dofile()`, `load()`, `loadfile()` or `loadstring()`).

In youtube-dl's case, it makes use of Python's `lambda` annonymous
functions to run what JSInterpreter returns.

The syntax is:

lambda [List of arguments.]: [Expression/body.]

And also, specifically to JSInterpreter's case, the `call_function`
function that is defined inside it is also allowed to do so.

It's also important to note that there is also the YouTube All HTML 5
extension, and the ViewTube GreaseMonkey userscript. I don't know yet if
they try compiling and/or executing the JS code somehow, but it would be
worth studying/checking.