Start: Disable copying a ThumbnailSource

Author: chennes

src/Mod/Start/App/ThumbnailSource.h

@@ -50,6 +50,12 @@ class ThumbnailSource: public QRunnable
     explicit ThumbnailSource(QString file);
     ~ThumbnailSource() override;
 
+    // Don't make copies of a ThumbnailSource (it's probably running a process, what would it mean
+    // to copy it?):
+    ThumbnailSource(ThumbnailSource&) = delete;
+    ThumbnailSource(ThumbnailSource&&) = delete;
+    ThumbnailSource operator=(const ThumbnailSource&) = delete;
+
     void run() override;
 
     ThumbnailSourceSignals* signals();