[Live-devel] GET_PARAMETER as liveness command problem

[Sergei Gagarin]

Proxy server can use GET_PARAMETER command with empty parameter
name as session liveness command.

In function ProxyRTSPClient::sendLivenessCommand (file ProxyServerMediaSession.cpp)
we see this code:
rtspClient->sendGetParameterCommand(*sess, ::continueAfterGET_PARAMETER, "", rtspClient->auth());
Here "" means parameter name.

It results in RTSP request to backend server containing "Content-Length" field
without real content.

Some servers (I noted it with VLC 2.0.8, did not check newer version) treat this
as error and return error 451 ("Parameter Not Understood").

I propose to replace "" with NULL. In this case no "Content-Length" field
in RTSP request.
Or modify RTSPClient::sendGetParameterCommand (file RTSPClient.cpp)
to ignore zero length parameter names.