Fixed crash on MacOS by disabling drag-and-drop in directories view

src/directories.cc

@@ -10,6 +10,16 @@ bool Directories::TreeStore::row_drop_possible_vfunc(const Gtk::TreeModel::Path
   return true;
 }
 
+bool Directories::TreeStore::row_draggable_vfunc(const TreeModel::Path &path) const {
+  // Drag and drop does not work on MacOS anymore
+  // TODO june 2018, see if this issue has been fixed
+  #ifdef __APPLE__
+    return false;
+  #else
+    return Gtk::TreeStore::row_draggable_vfunc(path);
+  #endif
+}
+
 bool Directories::TreeStore::drag_data_get_vfunc(const TreeModel::Path &path, Gtk::SelectionData &selection_data) const {
   // Workaround for MacOS crash when dragging a path for instance inside dir/subdir
 #ifdef __APPLE__

src/directories.h

@@ -27,6 +27,7 @@ class Directories : public Gtk::ListViewText {
     TreeStore() {}
     
     bool row_drop_possible_vfunc(const Gtk::TreeModel::Path &path, const Gtk::SelectionData &selection_data) const override;
+    bool row_draggable_vfunc(const TreeModel::Path &path) const override;
     bool drag_data_get_vfunc(const TreeModel::Path &path, Gtk::SelectionData &selection_data) const override;
     bool drag_data_received_vfunc(const TreeModel::Path &path, const Gtk::SelectionData &selection_data) override;
     bool drag_data_delete_vfunc (const Gtk::TreeModel::Path &path) override;