fix(qgsfeaturepool): cache management - fixes qgis#58113

Geometry checker does not work with memory layers, so we change
how the cache in the QgsFeaturePool object is managed, to refresh it
more often.

src/analysis/vector/geometry_checker/qgsfeaturepool.cpp

@@ -58,6 +58,7 @@ bool QgsFeaturePool::getFeature( QgsFeatureId id, QgsFeature &feature )
   {
     // Feature not in cache, retrieve from layer
     // TODO: avoid always querying all attributes (attribute values are needed when merging by attribute)
+    mFeatureSource = std::make_unique<QgsVectorLayerFeatureSource>( mLayer );
     if ( !mFeatureSource->getFeatures( QgsFeatureRequest( id ) ).nextFeature( feature ) )
     {
       return false;

src/analysis/vector/geometry_checker/qgsvectorlayerfeaturepool.cpp

@@ -137,12 +137,14 @@ void QgsVectorLayerFeaturePool::onGeometryChanged( QgsFeatureId fid, const QgsGe
 {
   Q_UNUSED( geometry )
 
-  if ( isFeatureCached( fid ) )
-  {
-    QgsFeature feature;
-    getFeature( fid, feature );
-    refreshCache( feature );
-  }
+  // Always update the cache and the spatial index on geometry change.
+  // A feature that was not in the cache previously might now have to be.
+  // For instance a geometry that was not in a previously requested area was not cached,
+  // but if it is now in the area it will be correctly added
+
+  QgsFeature feature;
+  getFeature( fid, feature );
+  refreshCache( feature );
 }
 
 void QgsVectorLayerFeaturePool::onFeatureDeleted( QgsFeatureId fid )

tests/src/geometry_checker/testqgsvectorlayerfeaturepool.cpp

@@ -140,29 +140,21 @@ void TestQgsVectorLayerFeaturePool::changeGeometry()
 
   // Update a feature to be outside the AOI
   feat.setGeometry( QgsGeometry::fromWkt( QStringLiteral( "Polygon((100 100, 110 100, 110 110, 100 110, 100 100))" ) ) );
-  vl->updateFeature( feat );
+  vl->updateFeature( feat );  // updates the geometry and triggers refreshing the cache
 
-  // Still working on the cached data
+  // Now no feature inside the AOI
   const QgsFeatureIds ids3 = pool.getIntersects( QgsRectangle( 0, 0, 10, 10 ) );
-  QCOMPARE( ids3.size(), 1 );
-
-  // Repopulate the cache
+  QCOMPARE( ids3.size(), 0 );
   const QgsFeatureIds ids4 = pool.getFeatures( QgsFeatureRequest().setFilterRect( QgsRectangle( 0, 0, 10, 10 ) ) );
   QCOMPARE( ids4.size(), 0 );
 
-  // Still working on the cached data
-  const QgsFeatureIds ids5 = pool.getIntersects( QgsRectangle( 0, 0, 10, 10 ) );
-  QCOMPARE( ids5.size(), 0 );
-
   // Update a feature to be inside the AOI
   feat.setGeometry( QgsGeometry::fromWkt( QStringLiteral( "Polygon((0 0, 10 0, 10 10, 0 10, 0 0))" ) ) );
-  vl->updateFeature( feat );
+  vl->updateFeature( feat );  // updates the geometry and triggers refreshing the cache
 
-  // Still cached
+  // Now one feature inside the AOI again
   const QgsFeatureIds ids6 = pool.getIntersects( QgsRectangle( 0, 0, 10, 10 ) );
-  QCOMPARE( ids6.size(), 0 );
-
-  // One in there again
+  QCOMPARE( ids6.size(), 1 );
   const QgsFeatureIds ids7 = pool.getFeatures( QgsFeatureRequest().setFilterRect( QgsRectangle( 0, 0, 10, 10 ) ) );
   QCOMPARE( ids7.size(), 1 );
 }