Bug 275171 [Contributions] Customize Perspective action breaks editor pinning action
Using M7, I enabled editor pinning (i.e. Reuse editor) and pinned an editor using an action in the toolbar. I then disabled editor pinning ad then opened the customized perspective dialog. After this, enabling/disabling editor pinning does not make the Pin Editor action reappear.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/WorkbenchActionBuilder.java
((RetargetActionWithDefault)buildProjectAction).setDefaultHandler(buildHandler);
            }
        };
        getWindow().addPageListener(pageListener);
        prefListener = new Preferences.IPropertyChangeListener() {
            public void propertyChange(Preferences.PropertyChangeEvent event) {
                if (event.getProperty().equals(
                        ResourcesPlugin.PREF_AUTO_BUILDING)) {
                   	updateBuildActions(false);
                }
            }
        };
        ResourcesPlugin.getPlugin().getPluginPreferences()
                .addPropertyChangeListener(prefListener);
        
        
        propPrefListener = new IPropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent event) {
                if (event.getProperty().equals(
						IPreferenceConstants.REUSE_EDITORS_BOOLEAN)) {
                    if (window.getShell() != null
                            && !window.getShell().isDisposed()) {
                        
                        window.getShell().getDisplay().syncExec(new Runnable() {
                            public void run() {
                                updatePinActionToolbar();
                            }
                        });
                    }
                }