Fix use after free of NetCamView

Someone was connecting a singal to a lambda capturing this, and never disconnecting it in the destructor. Capturing this is DANGEROUS, kids, don't do this at home.

src/video/netcamview.cpp

@@ -56,16 +56,16 @@ NetCamView::NetCamView(int friendId, QWidget* parent)
     frameLayout->setMargin(0);
 
     updateRatio();
-    connect(selfVideoSurface, &VideoSurface::ratioChanged, this, &NetCamView::updateRatio);
+    connections += connect(selfVideoSurface, &VideoSurface::ratioChanged, this, &NetCamView::updateRatio);
 
-    connect(videoSurface, &VideoSurface::boundaryChanged, [this]()
+    connections += connect(videoSurface, &VideoSurface::boundaryChanged, [this]()
     {
         QRect boundingRect = videoSurface->getBoundingRect();
         updateFrameSize(boundingRect.size());
         selfFrame->setBoundary(boundingRect);
     });
 
-    connect(videoSurface, &VideoSurface::ratioChanged, [this]()
+    connections += connect(videoSurface, &VideoSurface::ratioChanged, [this]()
     {
         selfFrame->setMinimumWidth(selfFrame->minimumHeight() * selfVideoSurface->getRatio());
         QRect boundingRect = videoSurface->getBoundingRect();
@@ -73,12 +73,12 @@ NetCamView::NetCamView(int friendId, QWidget* parent)
         selfFrame->resetBoundary(boundingRect);
     });
 
-    connect(Core::getInstance(), &Core::selfAvatarChanged, [this](const QPixmap& pixmap)
+    connections += connect(Core::getInstance(), &Core::selfAvatarChanged, [this](const QPixmap& pixmap)
     {
         selfVideoSurface->setAvatar(pixmap);
     });
 
-    connect(Core::getInstance(), &Core::friendAvatarChanged, [this](int FriendId, const QPixmap& pixmap)
+    connections += connect(Core::getInstance(), &Core::friendAvatarChanged, [this](int FriendId, const QPixmap& pixmap)
     {
         if (this->friendId == FriendId)
             videoSurface->setAvatar(pixmap);
@@ -92,6 +92,12 @@ NetCamView::NetCamView(int friendId, QWidget* parent)
     videoMode.FPS = Settings::getInstance().getCamVideoFPS();
 }
 
+NetCamView::~NetCamView()
+{
+    for (QMetaObject::Connection conn : connections)
+        disconnect(conn);
+}
+
 void NetCamView::show(VideoSource *source, const QString &title)
 {
     setSource(source);

src/video/netcamview.h

@@ -21,6 +21,7 @@
 #define NETCAMVIEW_H
 
 #include "genericnetcamview.h"
+#include <QVector>
 
 class QHBoxLayout;
 struct vpx_image;
@@ -34,6 +35,7 @@ class NetCamView : public GenericNetCamView
 
 public:
     NetCamView(int friendId, QWidget *parent=0);
+    ~NetCamView();
 
     virtual void show(VideoSource* source, const QString& title);
     virtual void hide();
@@ -54,6 +56,7 @@ private:
     MovableWidget* selfFrame;
     int friendId;
     bool e = false;
+    QVector<QMetaObject::Connection> connections;
 };
 
 #endif // NETCAMVIEW_H