Do not set full layer cache when a filter rect is passed

Fixes #19468 - Attribute table: show features visible on
map is broken (and affects show all features, too)

Cherry picked from master 929ab27

src/core/qgsvectorlayercache.cpp

@@ -205,11 +205,12 @@ void QgsVectorLayerCache::requestCompleted( const QgsFeatureRequest &featureRequ
   // If a request is too large for the cache don't notify to prevent from indexing incomplete requests
   if ( fids.count() <= mCache.size() )
   {
-    Q_FOREACH ( QgsAbstractCacheIndex *idx, mCacheIndices )
+    for ( const auto &idx : qgis::as_const( mCacheIndices ) )
     {
       idx->requestCompleted( featureRequest, fids );
     }
-    if ( featureRequest.filterType() == QgsFeatureRequest::FilterNone )
+    if ( featureRequest.filterType() == QgsFeatureRequest::FilterNone &&
+         ( featureRequest.filterRect().isNull() || featureRequest.filterRect().contains( mLayer->extent() ) ) )
     {
       mFullCache = true;
     }

tests/src/core/testqgsvectorlayercache.cpp

@@ -53,6 +53,7 @@ class TestVectorLayerCache : public QObject
     void testFullCacheThroughRequest();
     void testCanUseCacheForRequest();
     void testCacheGeom();
+    void testFullCacheWithRect(); // Test that if rect is set then no full cache can exist, see #19468
 
     void onCommittedFeaturesAdded( const QString &, const QgsFeatureList & );
 
@@ -390,6 +391,33 @@ void TestVectorLayerCache::testCacheGeom()
   QVERIFY( !cache.hasFullCache() );
 }
 
+void TestVectorLayerCache::testFullCacheWithRect()
+{
+  QgsVectorLayerCache cache( mPointsLayer, mPointsLayer->dataProvider()->featureCount() );
+  // cache geometry
+  cache.setCacheGeometry( true );
+  QVERIFY( ! cache.hasFullCache() );
+  QgsFeatureRequest req;
+  req.setFilterRect( mPointsLayer->dataProvider()->extent().buffered( - mPointsLayer->dataProvider()->extent().width() / 2 ) );
+  QgsFeatureIterator it = cache.getFeatures( req );
+  QgsFeature f;
+  while ( it.nextFeature( f ) )
+  {
+    QVERIFY( f.hasGeometry() );
+  }
+  QVERIFY( ! cache.hasFullCache() );
+
+  // Filter rect contains extent
+  req.setFilterRect( mPointsLayer->dataProvider()->extent().buffered( 1 ) );
+  it = cache.getFeatures( req );
+  while ( it.nextFeature( f ) )
+  {
+    QVERIFY( f.hasGeometry() );
+  }
+  QVERIFY( cache.hasFullCache() );
+
+}
+
 void TestVectorLayerCache::onCommittedFeaturesAdded( const QString &layerId, const QgsFeatureList &features )
 {
   Q_UNUSED( layerId )