added max chunk check on recv

[seanmcevoy]

this fix allows yaws to receive data over 64MB in size. open an erlang shell, start a tcp listener, send 256M + 1B and connect to it with:

spawn(fun() -> {ok,LS} = gen_tcp:listen(3456,[{reuseaddr, true}, {active, false}, binary]), {ok,SS} = gen_tcp:accept(LS), gen_tcp:send(SS,crypto:strong_rand_bytes((4 * 64 * 1024 * 1024) + 1)), receive stop -> ok end end). {ok,RS} = gen_tcp:connect("localhost",3456,[{reuseaddr, true}, {active, false}, binary]).

then on the receive side note that this can only be consumed in chunks of 64MB or less: gen_tcp:recv(SS, (64 * 1024 * 1024) + 0, 1000). gen_tcp:recv(SS, (64 * 1024 * 1024) + 1, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 0, 1000). gen_tcp:recv(RS, (64 * 1024 * 1024) + 1, 1000). gen_tcp:recv(RS, 1, 1000).

in our application all uploads of files greater than 64MB fail with enomem in the same way as demonstrated here. this change works in our application at least.

[avtobiff]

Thanks for your PR!

Please add a test for the new behaviour.

Please write a longer commit message describing the change. (Parts of the PR's description are good candidates of info describing the reason and method for the change.)