[#1956] Fix issue in multi-comp edit during undo operation

At least I hope this fixes it; it was a weird bug and hard to replicate...

core/src/net/sf/openrocket/rocketcomponent/AxialStage.java

@@ -241,6 +241,7 @@ public class AxialStage extends ComponentAssembly implements FlightConfigurableC
 	@Override
 	public void clearConfigListeners() {
 		super.clearConfigListeners();
+		// StageSeparationConfiguration also has config listeners, so clear them as well
 		StageSeparationConfiguration thisConfig = getSeparationConfiguration();
 		thisConfig.clearConfigListeners();
 	}

core/src/net/sf/openrocket/rocketcomponent/BodyTube.java

@@ -549,6 +549,7 @@ public class BodyTube extends SymmetricComponent implements BoxBounded, MotorMou
 	@Override
 	public void clearConfigListeners() {
 		super.clearConfigListeners();
+		// The motor config also has listeners, so clear them as well
 		getDefaultMotorConfig().clearConfigListeners();
 	}
 }

core/src/net/sf/openrocket/rocketcomponent/InnerTube.java

@@ -482,6 +482,7 @@ public class InnerTube extends ThicknessRingComponent implements AxialPositionab
 	@Override
 	public void clearConfigListeners() {
 		super.clearConfigListeners();
+		// The motor config also has listeners, so clear them as well
 		getDefaultMotorConfig().clearConfigListeners();
 	}
 	

core/src/net/sf/openrocket/rocketcomponent/NoseCone.java

@@ -1,14 +1,9 @@
 package net.sf.openrocket.rocketcomponent;
 
-import net.sf.openrocket.appearance.Appearance;
-import net.sf.openrocket.appearance.Decal;
 import net.sf.openrocket.l10n.Translator;
 import net.sf.openrocket.preset.ComponentPreset;
 import net.sf.openrocket.preset.ComponentPreset.Type;
 import net.sf.openrocket.startup.Application;
-import net.sf.openrocket.util.StateChangeListener;
-
-import java.util.EventObject;
 
 /**
  * Rocket nose cones of various types.  Implemented as a transition with the
@@ -205,7 +200,7 @@ public class NoseCone extends Transition implements InsideColorComponent {
 			return;
 		}
 
-		boolean previousByPass = getBypassComponentChangeEvent();
+		boolean previousByPass = isBypassComponentChangeEvent();
 		setBypassChangeEvent(true);
 		if (flipped) {
 			setForeRadius(getAftRadiusNoAutomatic());

core/src/net/sf/openrocket/rocketcomponent/RecoveryDevice.java

@@ -177,6 +177,7 @@ public abstract class RecoveryDevice extends MassObject implements FlightConfigu
 	@Override
 	public void clearConfigListeners() {
 		super.clearConfigListeners();
+		// The DeploymentConfiguration also has listeners, so clear them as well
 		DeploymentConfiguration thisConfig = getDeploymentConfigurations().getDefault();
 		thisConfig.clearConfigListeners();
 	}

core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java

@@ -448,6 +448,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		}
 		// Make sure the config listeners aren't cloned
 		clone.configListeners = new LinkedList<>();
+		clone.bypassComponentChangeEvent = false;
 		return clone;
 	}
 	
@@ -603,7 +604,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		for (RocketComponent listener : configListeners) {
 			listener.setBypassChangeEvent(false);
 			listener.setMassOverridden(o);
-			listener.setBypassChangeEvent(false);
+			listener.setBypassChangeEvent(true);
 		}
 
 		if (massOverridden == o) {
@@ -2277,7 +2278,11 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		this.bypassComponentChangeEvent = newValue;
 	}
 
-	public boolean getBypassComponentChangeEvent() {
+	/**
+	 * Returns whether the current component if ignoring ComponentChangeEvents.
+	 * @return true if the component is ignoring ComponentChangeEvents.
+	 */
+	public boolean isBypassComponentChangeEvent() {
 		return this.bypassComponentChangeEvent;
 	}
 
@@ -2287,7 +2292,18 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	 * @return true if listener was successfully added, false if not
 	 */
 	public boolean addConfigListener(RocketComponent listener) {
-		if (listener == null || configListeners.contains(listener) || listener == this) {
+		if (isBypassComponentChangeEvent()) {
+			// This is a precaution. If you are multi-comp editing and the current component is bypassing events,
+			// the editing will be REALLY weird, see GitHub issue #1956.
+			throw new IllegalStateException("Cannot add config listener while bypassing events");
+		}
+		if (listener == null) {
+			return false;
+		}
+		if (listener.getConfigListeners().size() > 0) {
+			throw new IllegalArgumentException("Listener already has config listeners");
+		}
+		if (configListeners.contains(listener) || listener == this) {
 			return false;
 		}
 		configListeners.add(listener);
@@ -2555,6 +2571,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 		this.displayOrder_side = src.displayOrder_side;
 		this.displayOrder_back = src.displayOrder_back;
 		this.configListeners = new LinkedList<>();
+		this.bypassComponentChangeEvent = false;
 		if (this instanceof InsideColorComponent && src instanceof InsideColorComponent) {
 			InsideColorComponentHandler icch = new InsideColorComponentHandler(this);
 			icch.copyFrom(((InsideColorComponent) src).getInsideColorComponentHandler());

swing/src/net/sf/openrocket/gui/main/DesignPanel.java

@@ -105,6 +105,7 @@ public class DesignPanel extends JSplitPane {
                     // Double-click
                     if ((e.getButton() == MouseEvent.BUTTON1) && (e.getClickCount() == 2) && !ComponentConfigDialog.isDialogVisible()) {
                         RocketComponent component = (RocketComponent) selPath.getLastPathComponent();
+                        component.clearConfigListeners();
 
                         // Multi-component edit if shift/meta key is pressed
                         if ((e.isShiftDown() || e.isMetaDown()) && tree.getSelectionPaths() != null) {

swing/src/net/sf/openrocket/gui/main/RocketActions.java

@@ -985,6 +985,7 @@ public class RocketActions {
 					ComponentConfigDialog.disposeDialog();
 
 				RocketComponent component = components.get(0);
+				component.clearConfigListeners();
 				if (components.size() > 1) {
 					for (int i = 1; i < components.size(); i++) {
 						RocketComponent listener = components.get(i);

swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java

@@ -636,6 +636,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 			if (event.isShiftDown() || event.isMetaDown()) {
 				List<TreePath> paths = new ArrayList<>(Arrays.asList(selectionModel.getSelectionPaths()));
 				RocketComponent component = selectedComponents.get(selectedComponents.size() - 1);
+				component.clearConfigListeners();
 
 				// Make sure the clicked component is selected
 				for (RocketComponent c : clicked) {