Rule based renderer: check for scale in rulesForFeature

src/core/symbology/qgsrulebasedrenderer.cpp

@@ -246,7 +246,7 @@ QgsLegendSymbolList QgsRuleBasedRenderer::Rule::legendSymbolItems( int currentLe
 
 bool QgsRuleBasedRenderer::Rule::isFilterOK( const QgsFeature &f, QgsRenderContext *context ) const
 {
-  if ( ! mFilter || mElseRule )
+  if ( ! mFilter || mElseRule || ! context )
     return true;
 
   context->expressionContext().setFeature( f );
@@ -647,7 +647,7 @@ QSet<QString> QgsRuleBasedRenderer::Rule::legendKeysForFeature( const QgsFeature
 QgsRuleBasedRenderer::RuleList QgsRuleBasedRenderer::Rule::rulesForFeature( const QgsFeature &feature, QgsRenderContext *context, bool onlyActive )
 {
   RuleList lst;
-  if ( !isFilterOK( feature, context ) )
+  if ( ! isFilterOK( feature, context ) || ( context && ! isScaleOK( context->rendererScale() ) ) )
     return lst;
 
   if ( mSymbol )

tests/src/python/test_qgsrulebasedrenderer.py

@@ -150,12 +150,12 @@ def testWillRenderFeatureNestedElse(self):
         vl.setRenderer(QgsRuleBasedRenderer(rootrule))
         renderer = vl.renderer()
 
-        # Reunder with else rule and all activated
+        # Render with else rule and all activated
         renderer.startRender(ctx, vl.fields())
         self.assertTrue(renderer.willRenderFeature(ft, ctx))
         renderer.stopRender(ctx)
 
-        # Reunder with else rule where else is deactivated
+        # Render with else rule where else is deactivated
         renderer.rootRule().children()[1].setActive(False)
         renderer.startRender(ctx, vl.fields())
         self.assertFalse(renderer.willRenderFeature(ft, ctx))
@@ -333,6 +333,45 @@ def testConvertFromGraduatedRenderer(self):
         self.assertEqual(r.rootRule().children()[0].filterExpression(), '"id" >= 0.000000 AND "id" <= 1.000000')
         self.assertEqual(r.rootRule().children()[1].filterExpression(), '"id" > 1.000000 AND "id" <= 2.000000')
 
+    def testWillRenderFeatureTwoElse(self):
+        """Regression #21287, also test rulesForFeature since there were no tests any where and I've found a couple of issues"""
+
+        vl = self.mapsettings.layers()[0]
+        ft = vl.getFeature(0) # 'id' = 1
+
+        ctx = QgsRenderContext.fromMapSettings(self.mapsettings)
+        ctx.expressionContext().setFeature(ft)
+
+        # Create rulebased style
+        sym2 = QgsFillSymbol.createSimple({'color': '#71bd6c', 'outline_color': 'black'})
+        sym3 = QgsFillSymbol.createSimple({'color': '#1f78b4', 'outline_color': 'black'})
+        sym4 = QgsFillSymbol.createSimple({'color': '#ff00ff', 'outline_color': 'black'})
+
+        self.rx2 = QgsRuleBasedRenderer.Rule(sym2, 0, 0, '"id" = 200')
+        self.rx3 = QgsRuleBasedRenderer.Rule(sym3, 1000, 100000000, 'ELSE') # <<< - match this!
+        self.rx4 = QgsRuleBasedRenderer.Rule(sym4, 0.1, 999, 'ELSE')
+
+        rootrule = QgsRuleBasedRenderer.Rule(None)
+        rootrule.appendChild(self.rx2)
+        rootrule.appendChild(self.rx3)
+        rootrule.appendChild(self.rx4)  # <- failed in regression #21287
+
+        vl.setRenderer(QgsRuleBasedRenderer(rootrule))
+        renderer = vl.renderer()
+
+        # Render with else rule and all activated
+        renderer.startRender(ctx, vl.fields())
+        self.assertTrue(renderer.willRenderFeature(ft, ctx))
+
+        # No context? All rules
+        self.assertEqual(len(rootrule.rulesForFeature(ft)), 2)
+        self.assertTrue(set(rootrule.rulesForFeature(ft)), set([self.rx3, self.rx4]))
+
+        # With context: only the matching one
+        self.assertEqual(len(rootrule.rulesForFeature(ft, ctx)), 1)
+        self.assertEqual(rootrule.rulesForFeature(ft, ctx)[0], self.rx3)
+        renderer.stopRender(ctx)
+
 
 if __name__ == '__main__':
     unittest.main()