fix crash while using multi_socket_action

[uudiin]

No description provided.

[coveralls]

Coverage decreased (-0.03%) to 63.667% when pulling 5b296d1 on uudiin:master into 90c1777 on Lua-cURL:master.

[moteus]

Can you provide test case?

[moteus]

I see what your problem. Thanks for bug report.
But I am not sure how to properly fix it.
I can not find any documentation about when cURL may call callbacks.
I thouth it can call callbacks only during perform and socket_action calls.
But I found that timerfunction can be called during add_handle call.
So now question is can cURL call any easy callbacks in such cases and shuld I set
Lua state only for multi handle or for all easy also?

multi = curl.multi{
  timerfunction = on_curl_timeout;
  socketfunction = on_curl_action;
}

-- here cURL may call e.g. `timerfunction` .
coroutine.wrap(function() multi:add_handle(c) end)()

PS. It will be good if you have any simple testcase without any external deps.

[uudiin]

I will provide testcase later. it depend on libuv and luv(lua libuv)
it is a example based multi-uv.c in curl source tree (curl/docs/examples/multi-uv.c)

[moteus]

I know about this :). And I use this example to test on local machine.
But I think how easily run this on Appveyor.

[coveralls]

Coverage decreased (-0.03%) to 63.667% when pulling 209585a on uudiin:master into 90c1777 on Lua-cURL:master.

[moteus]

I have similar example uvwget
I make my PR wich fix this bug. But it also works with coroutines.
Can you test it?

[moteus]

Just to notice. you can use just easy:setopt_writefunction(table.insert, wget.data)

[uudiin]

Thank you, I got it