On Ubuntu 14.04.3 LTS, and pinta 1.3-3ubuntu0.14.04.2, when I open image, make selection, copy, paste, and move around and zoom in, I get this:


MONO_CAIRO_DEBUG_DISPOSE=1 pinta myfile.png

...

(Pinta:3551): GLib-GObject-WARNING **: Attempt to add property __gtksharp_11_Pinta_Gui_Widgets_CellRendererSurface::surface after class was initialised
Cairo.Pattern is leaking, programmer is missing a call to Dispose
Allocated from:
   at System.Environment.get_StackTrace()
   at Cairo.CairoDebug.OnAllocated(IntPtr obj)
   at Cairo.Pattern..ctor(IntPtr handle, Boolean owned)
   at Cairo.Gradient..ctor(IntPtr handle, Boolean owned)
   at Cairo.LinearGradient..ctor(Double x0, Double y0, Double x1, Double y1)
   at MonoDevelop.Components.Docking.CustomFrame.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Container.gtksharp_container_invoke_gtk_callback(IntPtr , IntPtr , IntPtr )
   at Gtk.Container+CallbackInvoker.Invoke(Gtk.Widget w)
   at MonoDevelop.Components.Docking.DockContainer.ForAll(Boolean include_internals, Gtk.Callback callback)
   at Gtk.Container.Forall_cb(IntPtr container, Boolean include_internals, IntPtr cb, IntPtr data)
   at Gtk.Widget.gtksharp_widget_base_expose_event(IntPtr , IntPtr )
   at Gtk.Widget.OnExposeEvent(Gdk.EventExpose evnt)
   at MonoDevelop.Components.Docking.DockContainer.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Pinta.MainClass.Main(System.String[] args)
Cairo.Pattern is leaking, programmer is missing a call to Dispose
Allocated from:
   at System.Environment.get_StackTrace()
   at Cairo.CairoDebug.OnAllocated(IntPtr obj)
   at Cairo.Pattern..ctor(IntPtr handle, Boolean owned)
   at Cairo.Gradient..ctor(IntPtr handle, Boolean owned)
   at Cairo.LinearGradient..ctor(Double x0, Double y0, Double x1, Double y1)
   at MonoDevelop.Components.Docking.CustomFrame.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Container.gtksharp_container_invoke_gtk_callback(IntPtr , IntPtr , IntPtr )
   at Gtk.Container+CallbackInvoker.Invoke(Gtk.Widget w)
   at MonoDevelop.Components.Docking.DockContainer.ForAll(Boolean include_internals, Gtk.Callback callback)
   at Gtk.Container.Forall_cb(IntPtr container, Boolean include_internals, IntPtr cb, IntPtr data)
   at Gtk.Widget.gtksharp_widget_base_expose_event(IntPtr , IntPtr )
   at Gtk.Widget.OnExposeEvent(Gdk.EventExpose evnt)
   at MonoDevelop.Components.Docking.DockContainer.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Pinta.MainClass.Main(System.String[] args)

(Pinta:3551): GLib-CRITICAL **: Source ID 235 was not found when attempting to remove it

(Pinta:3551): GLib-CRITICAL **: Source ID 200 was not found when attempting to remove it

(Pinta:3551): GLib-CRITICAL **: Source ID 149 was not found when attempting to remove it

(Pinta:3551): GLib-CRITICAL **: Source ID 223 was not found when attempting to remove it
...
(Pinta:3551): GLib-CRITICAL **: Source ID 197 was not found when attempting to remove it
Cairo.Pattern is leaking, programmer is missing a call to Dispose
Allocated from:
   at System.Environment.get_StackTrace()
   at Cairo.CairoDebug.OnAllocated(IntPtr obj)
   at Cairo.Pattern..ctor(IntPtr handle, Boolean owned)
   at Cairo.Gradient..ctor(IntPtr handle, Boolean owned)
   at Cairo.LinearGradient..ctor(Double x0, Double y0, Double x1, Double y1)
   at MonoDevelop.Components.Docking.CustomFrame.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Container.gtksharp_container_invoke_gtk_callback(IntPtr , IntPtr , IntPtr )
   at Gtk.Container+CallbackInvoker.Invoke(Gtk.Widget w)
   at MonoDevelop.Components.Docking.DockContainer.ForAll(Boolean include_internals, Gtk.Callback callback)
   at Gtk.Container.Forall_cb(IntPtr container, Boolean include_internals, IntPtr cb, IntPtr data)
   at Gtk.Widget.gtksharp_widget_base_expose_event(IntPtr , IntPtr )
   at Gtk.Widget.OnExposeEvent(Gdk.EventExpose evnt)
   at MonoDevelop.Components.Docking.DockContainer.OnExposeEvent(Gdk.EventExpose evnt)
   at Gtk.Widget.exposeevent_cb(IntPtr widget, IntPtr evnt)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at Pinta.MainClass.Main(System.String[] args)

(Pinta:3551): GLib-CRITICAL **: Source ID 1050 was not found when attempting to remove it

(Pinta:3551): GLib-CRITICAL **: Source ID 1041 was not found when attempting to remove it
...

The first stack dump  was right on the paste action.

I use the Mate desktop, if that matters...