http: Prevent assert on bad websocket data.

Common/Net/Sinks.cpp

@@ -164,6 +164,12 @@ bool InputSink::Skip(size_t bytes) {
 	return true;
 }
 
+void InputSink::Discard() {
+	read_ = 0;
+	write_ = 0;
+	valid_ = 0;
+}
+
 void InputSink::Fill() {
 	// Avoid small reads if possible.
 	if (BUFFER_SIZE - valid_ > PRESSURE) {

Common/Net/Sinks.h

@@ -19,6 +19,7 @@ public:
 	size_t TakeAtMost(char *buf, size_t bytes);
 	// Skip exactly this number of bytes, or fail.
 	bool Skip(size_t bytes);
+	void Discard();
 
 	bool Empty();
 	bool TryFill();

Core/Debugger/WebSocket.cpp

@@ -196,6 +196,7 @@ void HandleDebuggerRequest(const http::Request &request) {
 	}
 
 	delete ws;
+	request.In()->Discard();
 	UpdateConnected(-1);
 }