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
undoAction = ActionFactory.UNDO.create(window);
        register(undoAction);
        redoAction = ActionFactory.REDO.create(window);
        register(redoAction);
        closeAction = ActionFactory.CLOSE.create(window);
        register(closeAction);
        closeAllAction = ActionFactory.CLOSE_ALL.create(window);
        register(closeAllAction);
        closeOthersAction = ActionFactory.CLOSE_OTHERS.create(window);
        register(closeOthersAction);
        closeAllSavedAction = ActionFactory.CLOSE_ALL_SAVED.create(window);
        register(closeAllSavedAction);
        helpContentsAction = ActionFactory.HELP_CONTENTS.create(window);
        register(helpContentsAction);
        helpSearchAction = ActionFactory.HELP_SEARCH.create(window);
        register(helpSearchAction);
		
        dynamicHelpAction = ActionFactory.DYNAMIC_HELP.create(window);
        register(dynamicHelpAction);
        
        aboutAction = ActionFactory.ABOUT.create(window);
        aboutAction
                .setImageDescriptor(IDEInternalWorkbenchImages
                        .getImageDescriptor(IDEInternalWorkbenchImages.IMG_OBJS_DEFAULT_PROD));
        register(aboutAction);
        openPreferencesAction = ActionFactory.PREFERENCES.create(window);
        register(openPreferencesAction);
        
        makeFeatureDependentActions(window);