Remove layers from the edit buffer group

Layers are removed togheter with removal from project
Fix #59828

src/core/project/qgsproject.cpp

@@ -2726,6 +2726,15 @@ void QgsProject::onMapLayersRemoved( const QList<QgsMapLayer *> &layers )
 
   if ( !mBlockSnappingUpdates && mSnappingConfig.removeLayers( layers ) )
     emit snappingConfigChanged( mSnappingConfig );
+
+  for ( QgsMapLayer *layer : layers )
+  {
+    QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
+    if ( ! vlayer )
+      continue;
+
+    mEditBufferGroup.removeLayer( vlayer );
+  }
 }
 
 void QgsProject::cleanTransactionGroups( bool force )

src/core/vector/qgsvectorlayereditbuffergroup.cpp

@@ -34,6 +34,11 @@ void QgsVectorLayerEditBufferGroup::addLayer( QgsVectorLayer *layer )
   mLayers.insert( layer );
 }
 
+void QgsVectorLayerEditBufferGroup::removeLayer( QgsVectorLayer *layer )
+{
+  mLayers.remove( layer );
+}
+
 void QgsVectorLayerEditBufferGroup::clear()
 {
   mLayers.clear();

src/core/vector/qgsvectorlayereditbuffergroup.h

@@ -50,7 +50,14 @@ class CORE_EXPORT QgsVectorLayerEditBufferGroup : public QObject
     void addLayer( QgsVectorLayer *layer );
 
     /**
-     * Remove all layers from this edit buffer group
+     * Remove a layer from this edit buffer group.
+     *
+     * \since QGIS 3.42
+     */
+    void removeLayer( QgsVectorLayer *layer );
+
+    /**
+     * Remove all layers from this edit buffer group.
      */
     void clear();
 

tests/src/python/test_qgsvectorlayereditbuffergroup.py

@@ -299,6 +299,34 @@ def testCircularRelations(self):
         self.assertTrue(success)
         self.assertFalse(editBufferGroup.isEditing())
 
+    def testRemoveLayer(self):
+        memoryLayer_a = QgsVectorLayer(
+            "Point?crs=epsg:4326&field=id:integer&field=id_b", "testA", "memory"
+        )
+        self.assertTrue(memoryLayer_a.isValid())
+
+        memoryLayer_b = QgsVectorLayer(
+            "Point?crs=epsg:4326&field=id:integer&field=id_a", "testB", "memory"
+        )
+        self.assertTrue(memoryLayer_b.isValid())
+
+        project = QgsProject.instance()
+        project.addMapLayer(memoryLayer_a)
+        project.addMapLayer(memoryLayer_b)
+
+        project.setTransactionMode(Qgis.TransactionMode.BufferedGroups)
+
+        editBufferGroup = project.editBufferGroup()
+
+        project.removeMapLayer(memoryLayer_a.id())
+
+        self.assertNotIn(memoryLayer_a, editBufferGroup.layers())
+        self.assertIn(memoryLayer_b, editBufferGroup.layers())
+
+        # Chack that no crash happens (#59828)
+        project.startEditing()
+        project.commitChanges()
+
 
 if __name__ == '__main__':
     unittest.main()