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
}
    }
    /**
     * Asks this part to take focus within the workbench.
     * <p>
     * Clients should not call this method (the workbench calls this method at
     * appropriate times).
     * </p>
     */
    public void setFocus() {
        if ((editorComposite != null) && (lastNavigatedText == null)
                && (currentText == null))
            editorComposite.setFocus();
    }
    /**
     * Sets the styled text's link (blue) ranges
     */
    private void setLinkRanges(StyledText styledText, int[][] linkRanges) {
        
        Color fg = JFaceColors.getHyperlinkText(styledText.getShell()
                .getDisplay());
        for (int i = 0; i < linkRanges.length; i++) {
            StyleRange r = new StyleRange(linkRanges[i][0], linkRanges[i][1],
                    fg, null);
            styledText.setStyleRange(r);
            hyperlinkRanges.add(r);
        }
    }
}