Bug 117925 [Intro] Misleading exception message in WelcomeEditor.init()
... it says it expects an IFileEditorInput, but it actually checks for WelcomeEditorInput. Suggested patch appended.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/WelcomeEditor.java
return infoArea;
    }
    /**
     * Creates the SWT controls for this workbench part.
     * <p>
     * Clients should not call this method (the workbench calls this method at
     * appropriate times).
     * </p>
     * <p>
     * For implementors this is a multi-step process:
     * <ol>
     *   <li>Create one or more controls within the parent.</li>
     *   <li>Set the parent layout as needed.</li>
     *   <li>Register any global actions with the <code>IActionService</code>.</li>
     *   <li>Register any popup menus with the <code>IActionService</code>.</li>
     *   <li>Register a selection provider with the <code>ISelectionService</code>
     *     (optional). </li>
     * </ol>
     * </p>
     *
     * @param parent the parent control
     */
    public void createPartControl(Composite parent) {
        
        readFile();
        if (parser == null)
            return;
        handCursor = new Cursor(parent.getDisplay(), SWT.CURSOR_HAND);
        busyCursor = new Cursor(parent.getDisplay(), SWT.CURSOR_WAIT);
        editorComposite = new Composite(parent, SWT.NONE);