exml_event.c: enif_open_resource_type for "parser_pointer" does not specify the destructor function.

[RGafiyatullin]

The following snippet contains some helper funs I would like to use to demonstrate the issue.
Just paste them into your REPL: https://gist.github.com/RGafiyatullin/675b97dc76c69d8a7c00 .

The leaky case (current esl/master): https://gist.github.com/RGafiyatullin/9cefce33bb22f3350cf0 .
The fixed case (current RGafiyatullin/master): https://gist.github.com/RGafiyatullin/4b895d6282b43d78dc42 .

Bits of reasoning:

• The mandatory exml_event:free_parser/1 usage is not an option as it is a slightly less expected behaviour rather than a proper resource cleanup upon garbage collection. (The iodevices / ets's / dets's / you-name-it's usually get disposed upon the owner's termination ).
• exml_event:free_parser/1 being bound to exml_event:reset_parser/1 is IMHO a necessity since any attempt to use exml_event:parse/2 with the resource being previously freed leads to a VM crash. The ErlangVM is not expected to crash with a segfault in case of a mistake in Erlang code.

[RGafiyatullin]

Ouch. My apologies.
Merging paulgray/master will do the same: https://github.com/paulgray/exml/blob/master/c_src/exml_event.c

[paulgray]

@RGafiyatullin actually the latest commit is your code ported to the upstream repo.
Good catch!

[michalwski]

@RGafiyatullin I've merged your changes into esl/exml master. Many thanks!