ComboBox: fixed StackOverflowError when using single renderer instance in multiple comboboxes (regression since commit 4507ce359d)

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java

@@ -791,14 +791,20 @@ public class FlatComboBoxUI
 			if( oldBorder == this )
 				return; // already installed
 
+			// component already has a padding border --> uninstall it
+			// (may happen if single renderer instance is used in multiple comboboxes)
+			if( oldBorder instanceof CellPaddingBorder )
+				((CellPaddingBorder)oldBorder).uninstall();
+
 			// this border can be installed only at one component
+			// (may happen if a renderer returns varying components)
 			uninstall();
 
 			// remember component where this border was installed for uninstall
 			rendererComponent = jc;
 
 			// remember old border and replace it
-			rendererBorder = oldBorder;
+			rendererBorder = jc.getBorder();
 			rendererComponent.setBorder( this );
 		}
 

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatCustomBordersTest.java

@@ -47,6 +47,7 @@ public class FlatCustomBordersTest
 	FlatCustomBordersTest() {
 		initComponents();
 		applyCustomBorders();
+		applySpecialComboBoxRenderers();
 
 		DefaultComboBoxModel<String> model = new DefaultComboBoxModel<>( new String[] {
 			"text",
@@ -123,6 +124,33 @@ public class FlatCustomBordersTest
 		applyCustomComboBoxRendererBorder( comboBox28, null );
 	}
 
+	@SuppressWarnings( "unchecked" )
+	private void applySpecialComboBoxRenderers() {
+		BasicComboBoxRenderer sharedRenderer = new BasicComboBoxRenderer();
+		sharedRenderer.setBorder( new LineBorder( ORANGE, UIScale.scale( 2 ) ) );
+		comboBox29.setRenderer( sharedRenderer );
+		comboBox30.setRenderer( sharedRenderer );
+
+		comboBox31.setRenderer( new ListCellRenderer<String>() {
+			JLabel l1 = new JLabel();
+			JLabel l2 = new JLabel();
+
+			@Override
+			public Component getListCellRendererComponent( JList<? extends String> list,
+				String value, int index, boolean isSelected, boolean cellHasFocus )
+			{
+				JLabel l = (index % 2 == 0) ? l1 : l2;
+				l.setText( (value != null) ? value.toString() : "" );
+				l.setBorder( new LineBorder( (index % 2 == 0) ? GREEN : RED, UIScale.scale( 2 ) ) );
+				l.setBackground( isSelected ? list.getSelectionBackground() : list.getBackground() );
+				l.setForeground( isSelected ? list.getSelectionForeground() : list.getForeground() );
+				l.setFont( list.getFont() );
+				l.setOpaque( true );
+				return l;
+			}
+		} );
+	}
+
 	private void applyCustomInsideBorder( JComponent c, String uiKey ) {
 		c.setBorder( new CompoundBorder( UIManager.getBorder( uiKey ), new LineBorder( RED, UIScale.scale( 3 ) ) ) );
 	}
@@ -231,6 +259,11 @@ public class FlatCustomBordersTest
 		textField6 = new JTextField();
 		textField7 = new JTextField();
 		textField8 = new JTextField();
+		label11 = new JLabel();
+		label12 = new JLabel();
+		comboBox29 = new JComboBox<>();
+		comboBox30 = new JComboBox<>();
+		comboBox31 = new JComboBox<>();
 
 		//======== this ========
 		setLayout(new MigLayout(
@@ -255,6 +288,8 @@ public class FlatCustomBordersTest
 			"[]" +
 			"[]" +
 			"[]" +
+			"[]para" +
+			"[]" +
 			"[]"));
 
 		//---- label1 ----
@@ -493,6 +528,17 @@ public class FlatCustomBordersTest
 		textField8.putClientProperty("JComponent.roundRect", true);
 		textField8.setText("text");
 		add(textField8, "cell 4 10");
+
+		//---- label11 ----
+		label11.setText("JComboBox with shared renderer:");
+		add(label11, "cell 1 11 2 1");
+
+		//---- label12 ----
+		label12.setText("JComboBox with renderer that uses varying components:");
+		add(label12, "cell 3 11 3 1");
+		add(comboBox29, "cell 1 12");
+		add(comboBox30, "cell 2 12");
+		add(comboBox31, "cell 3 12");
 		// JFormDesigner - End of component initialization  //GEN-END:initComponents
 	}
 
@@ -560,6 +606,11 @@ public class FlatCustomBordersTest
 	private JTextField textField6;
 	private JTextField textField7;
 	private JTextField textField8;
+	private JLabel label11;
+	private JLabel label12;
+	private JComboBox<String> comboBox29;
+	private JComboBox<String> comboBox30;
+	private JComboBox<String> comboBox31;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 
 	//---- class BorderWithIcon -----------------------------------------------

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatCustomBordersTest.jfd

@@ -6,7 +6,7 @@ new FormModel {
 		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[][fill][fill][fill][fill][fill][fill][fill]"
-			"$rowConstraints": "[][][][][][][][][][][]"
+			"$rowConstraints": "[][][][][][][][][][][]para[][]"
 		} ) {
 			name: "this"
 			add( new FormComponent( "javax.swing.JLabel" ) {
@@ -478,6 +478,42 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 4 10"
 			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "label11"
+				"text": "JComboBox with shared renderer:"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 11 2 1"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "label12"
+				"text": "JComboBox with renderer that uses varying components:"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 3 11 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JComboBox" ) {
+				name: "comboBox29"
+				auxiliary() {
+					"JavaCodeGenerator.typeParameters": "String"
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 12"
+			} )
+			add( new FormComponent( "javax.swing.JComboBox" ) {
+				name: "comboBox30"
+				auxiliary() {
+					"JavaCodeGenerator.typeParameters": "String"
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 2 12"
+			} )
+			add( new FormComponent( "javax.swing.JComboBox" ) {
+				name: "comboBox31"
+				auxiliary() {
+					"JavaCodeGenerator.typeParameters": "String"
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 3 12"
+			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
 			"size": new java.awt.Dimension( 915, 715 )