commit e6093782644b83c3c5112b1facf0a680c4005817
Author:     ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
AuthorDate: Wed May 8 13:52:32 2024 +0200
Commit:     ManoloFLTK <41016272+ManoloFLTK@users.noreply.github.com>
CommitDate: Wed May 8 13:52:32 2024 +0200

    Avoid possible dereferencing of null pointer (#971)

 src/Fl_Tree.cxx | 1 +
 1 file changed, 1 insertion(+)

diff --git src/Fl_Tree.cxx src/Fl_Tree.cxx
index a545a32..50f13b9 100644
--- src/Fl_Tree.cxx
+++ src/Fl_Tree.cxx
@@ -383,6 +383,7 @@ int Fl_Tree::handle(int e) {
     case FL_PUSH: {             // clicked on tree
       last_my = Fl::event_y();  // save for dragging direction..
       if (Fl::visible_focus() && handle(FL_FOCUS)) Fl::focus(this);
+      if ( ! _root ) return(ret); // issue #971
       Fl_Tree_Item *item = _root->find_clicked(_prefs, 0);
       // Tell FL_DRAG what was pushed
       _lastpushed = item ? item->event_on_collapse_icon(_prefs) ? PUSHED_OPEN_CLOSE  // open/close icon clicked