#14505 caf: Add cafTestApplication repro for reentrant property editor rebuild

Adds a ReentrantEditorRebuild demo object that rebuilds all property editors from inside fieldChangedByUi(), while Qt is still executing QLineEdit::focusOutEvent. Type a value into Realization Filter and press Tab to trigger. The change handler drops both the line edit field and its parent group from the ui ordering, so PdmUiFormLayoutObjectEditor::configureAndUpdateUi() tears down widgets that are still in use further up the stack. Uncheck Rebuild Layout On Change to run the same edit without the reentrant rebuild.

Fwk/AppFwk/cafTests/cafTestApplication/CMakeLists.txt

@@ -64,6 +64,8 @@ set(PROJECT_FILES
     PdmObjects/OptionalFields.cpp
     PdmObjects/ValidationTest.h
     PdmObjects/ValidationTest.cpp
+    PdmObjects/ReentrantEditorRebuild.h
+    PdmObjects/ReentrantEditorRebuild.cpp
 )
 
 qt_add_executable(

Fwk/AppFwk/cafTests/cafTestApplication/MainWindow.cpp

@@ -13,6 +13,7 @@
 #include "PdmObjects/LineEditAndPushButtons.h"
 #include "PdmObjects/ManyGroups.h"
 #include "PdmObjects/OptionalFields.h"
+#include "PdmObjects/ReentrantEditorRebuild.h"
 #include "PdmObjects/SingleEditorPdmObject.h"
 #include "PdmObjects/SmallDemoPdmObject.h"
 #include "PdmObjects/SmallDemoPdmObjectA.h"
@@ -196,6 +197,7 @@ void MainWindow::buildTestModel()
     m_testRoot->objects.push_back( new LineEditAndPushButtons );
     m_testRoot->objects.push_back( new LabelsAndHyperlinks );
     m_testRoot->objects.push_back( new OptionalFields );
+    m_testRoot->objects.push_back( new ReentrantEditorRebuild );
 
     auto tamComboBox = new TamComboBox;
     m_testRoot->objects.push_back( tamComboBox );

Fwk/AppFwk/cafTests/cafTestApplication/PdmObjects/ReentrantEditorRebuild.cpp

@@ -0,0 +1,89 @@
+#include "ReentrantEditorRebuild.h"
+
+#include "cafPdmUiLineEditor.h"
+#include "cafPdmUiOrdering.h"
+
+CAF_PDM_SOURCE_INIT( ReentrantEditorRebuild, "ReentrantEditorRebuild" );
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+ReentrantEditorRebuild::ReentrantEditorRebuild()
+    : m_hideFilterGroup( false )
+{
+    CAF_PDM_InitObject( "Reentrant Editor Rebuild", "", "", "" );
+
+    CAF_PDM_InitField( &m_realizationFilter,
+                       "RealizationFilter",
+                       QString(),
+                       "Realization Filter",
+                       "",
+                       "Type a value here and press Tab",
+                       "" );
+
+    CAF_PDM_InitField( &m_statusField, "Status", QString( "Type into Realization Filter, then press Tab" ), "Status", "", "", "" );
+    m_statusField.uiCapability()->setUiReadOnly( true );
+
+    CAF_PDM_InitField( &m_rebuildLayoutOnChange,
+                       "RebuildLayoutOnChange",
+                       true,
+                       "Rebuild Layout On Change",
+                       "",
+                       "Rebuild all property editors from inside fieldChangedByUi()",
+                       "" );
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void ReentrantEditorRebuild::fieldChangedByUi( const caf::PdmFieldHandle* changedField,
+                                               const QVariant&            oldValue,
+                                               const QVariant&            newValue )
+{
+    if ( changedField == &m_realizationFilter )
+    {
+        m_statusField = "Committed value: " + m_realizationFilter();
+
+        if ( m_rebuildLayoutOnChange )
+        {
+            // Drop the group that parents the line edit, and rebuild every property editor while
+            // still inside QLineEdit::focusOutEvent. This mirrors
+            // RimSumoDataSource::fieldChangedByUi() -> RimSummaryEnsembleSumo::onRealizationSelectionChanged().
+            m_hideFilterGroup = true;
+
+            updateAllRequiredEditors();
+        }
+    }
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void ReentrantEditorRebuild::defineUiOrdering( QString uiConfigName, caf::PdmUiOrdering& uiOrdering )
+{
+    uiOrdering.add( &m_statusField );
+    uiOrdering.add( &m_rebuildLayoutOnChange );
+
+    if ( !m_hideFilterGroup )
+    {
+        // The line edit lives inside this group. When both the field and the group disappear from
+        // the ui ordering, PdmUiFormLayoutObjectEditor::configureAndUpdateUi() first deletes the
+        // field editor, whose destructor only calls deleteLater() on the QLineEdit, and then
+        // destroys the parent QMinimizePanel with a raw delete. ~QWidget destroys its children
+        // immediately, so the QLineEdit is gone before the pending deleteLater() can run.
+        auto group = uiOrdering.addNewGroup( "Filter" );
+        group->add( &m_realizationFilter );
+    }
+
+    uiOrdering.addNewButton( "Restore Filter Group", [this]() { restoreFilterGroup(); } );
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void ReentrantEditorRebuild::restoreFilterGroup()
+{
+    m_hideFilterGroup = false;
+
+    updateAllRequiredEditors();
+}

Fwk/AppFwk/cafTests/cafTestApplication/PdmObjects/ReentrantEditorRebuild.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include "cafPdmField.h"
+#include "cafPdmObject.h"
+
+//==================================================================================================
+/// Reproduction of https://github.com/OPM/ResInsight/issues/14505
+///
+/// Rebuilding the property editors from inside fieldChangedByUi() destroys widgets that Qt is
+/// still executing an event handler on, giving a use-after-free in QLineEdit::focusOutEvent.
+///
+/// Steps to reproduce:
+///   1. Select this object in the tree view so the property editor is shown.
+///   2. Type a value into "Realization Filter".
+///   3. Press Tab. Do not press Enter, the focus-out path is the dangerous one. Enter is handled
+///      by PdmUiLineEditor::eventFilter, which calls slotEditingFinished() outside focusOutEvent.
+///
+/// Uncheck "Rebuild Layout On Change" to get the same edit without the reentrant rebuild.
+//==================================================================================================
+class ReentrantEditorRebuild : public caf::PdmObject
+{
+    CAF_PDM_HEADER_INIT;
+
+public:
+    ReentrantEditorRebuild();
+
+    void fieldChangedByUi( const caf::PdmFieldHandle* changedField, const QVariant& oldValue, const QVariant& newValue ) override;
+
+private:
+    void defineUiOrdering( QString uiConfigName, caf::PdmUiOrdering& uiOrdering ) override;
+
+    void restoreFilterGroup();
+
+private:
+    caf::PdmField<QString> m_realizationFilter;
+    caf::PdmField<QString> m_statusField;
+    caf::PdmField<bool>    m_rebuildLayoutOnChange;
+
+    bool m_hideFilterGroup;
+};