fixes some problems with WebServerThrad

- use -h& command so the thread does end
- set the QRCore in the constructor
- try to disable the websever with =h-

src/webserverthread.cpp

@@ -1,14 +1,78 @@
 #include "webserverthread.h"
+#include "qrcore.h"
+#include <cassert>
 
-WebServerThread::WebServerThread(QObject *parent) :
-    QThread(parent)
+WebServerThread::WebServerThread(QRCore *core, QObject *parent) :
+    QThread(parent),
+    core(core),
+    started(false)
 {
     // MEOW
 }
 
+WebServerThread::~WebServerThread()
+{
+    if (isRunning()) {
+        quit();
+        wait();
+    }
+}
+
+void WebServerThread::startServer()
+{
+    assert(nullptr != core);
+
+    if (!isRunning() && !started) {
+        QThread::start();
+    }
+}
+
+void WebServerThread::stopServer()
+{
+    assert(nullptr != core);
+
+    if (!isRunning() && started)
+    {
+        QThread::start();
+    }
+}
+
+bool WebServerThread::isStarted() const
+{
+    QMutexLocker locker(&mutex);
+    return started;
+}
+
 void WebServerThread::run() {
-    if (core == NULL)
+    QMutexLocker locker(&mutex);
+
+    if (core == nullptr)
         return;
     //eprintf ("Starting webserver!");
-    core->cmd ("=h");
+
+    toggleWebServer();
+}
+
+void WebServerThread::toggleWebServer()
+{
+    // access already locked
+
+    // see libr/core/rtr.c
+    // "=h", " port", "listen for http connections (r2 -qc=H /bin/ls)",
+    // "=h-", "", "stop background webserver",
+    // "=h*", "", "restart current webserver",
+    // "=h&", " port", "start http server in background)",
+
+    if (started) {
+        // after this the only reaction to this commands is:
+        // sandbox: connect disabled
+        // and the webserver is still running
+        // TODO: find out why
+        core->cmd("=h-");
+    } else {
+        core->cmd("=h&");
+    }
+
+    // cmd has no usefull return value for this commands, so just toogle the state
+    started = !started;
 }

src/webserverthread.h

@@ -2,20 +2,32 @@
 #define WEBSERVERTHREAD_H
 
 #include <QThread>
-#include "qrcore.h"
+#include <QMutex>
+
+class QRCore;
 
 class WebServerThread : public QThread
 {
     Q_OBJECT
 public:
-    QRCore *core;
-    explicit WebServerThread(QObject *parent = 0);
 
-signals:
+    explicit WebServerThread(QRCore *core, QObject *parent = 0);
+    ~WebServerThread();
+
+    void startServer();
+    void stopServer();
+
+    bool isStarted() const;
 
-public slots:
 private:
     void run();
+    using QThread::start;
+
+    void toggleWebServer();
+
+    mutable QMutex mutex;
+    QRCore *core;
+    bool   started;
 };
 
 #endif // WEBSERVERTHREAD_H