#14167 Fix table dropdown needing two clicks when moving to another row

The table model shares one field editor handle per column across all rows.
When an edit ends, the view schedules the editor widget for deletion with
deleteLater(), but the handle's QPointer stays valid until the deferred
deletion runs. Clicking a cell in the same column of another row reused that
doomed widget as the new cell editor, so it was destroyed right after
opening and the user had to click again. Moving horizontally was unaffected
since a different column uses a different editor handle.

Cancel the pending deferred deletion before handing the widget out again,
and guard against a null editor widget.

Fwk/AppFwk/cafUserInterface/cafPdmUiTableViewQModel.cpp

@@ -45,6 +45,9 @@
 #include "cafPdmUiOrdering.h"
 #include "cafPdmUiTableRowEditor.h"
 
+#include <QCoreApplication>
+#include <QEvent>
+
 namespace caf
 {
 //--------------------------------------------------------------------------------------------------
@@ -541,6 +544,15 @@ QWidget* PdmUiTableViewQModel::getEditorWidgetAndTransferOwnership( QWidget* par
         // using QPointer
         editor->createWidgets( parent );
         QWidget* editorWidget = editor->editorWidget();
+        if ( !editorWidget ) return nullptr;
+
+        // The editor handle is shared by every row in a column. When the edit on one cell ends, the view
+        // schedules its editor widget for deletion via deleteLater(). Moving to another cell in the same
+        // column reuses that very widget before the deferred deletion has run, so without this the widget
+        // is destroyed moments after the new editor opens - silently cancelling the edit and forcing the
+        // user to click a second time. Cancel the pending deletion so the reused widget stays alive.
+        QCoreApplication::removePostedEvents( editorWidget, QEvent::DeferredDelete );
+
         editorWidget->setParent( parent );
 
         return editorWidget;