Bug 129886 Delect a column contain the marge row which contain some item, Error message pop up
Details: Delect a column contain the marge row which contain some item, Error message pop up Setp: 1.New a library and add a 3*3 grid 2.Insert a label in cell(1,1) 3.Marge the cell of (1,1) and (1,2) 4.Delete column 1. Actual result: An error message pop up
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/editparts/TableEditPart.java
}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.core.facade.ITableAdaptHelper#caleVisualWidth(int)
	 */
	public int caleVisualWidth( int columnNumber )
	{
		assert columnNumber > 0;
		return TableUtil.caleVisualWidth( this, getColumn( columnNumber ) );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.core.facade.ITableAdaptHelper#caleVisualHeight(int)
	 */
	public int caleVisualHeight( int rowNumber )
	{
		return TableUtil.caleVisualHeight( this, getRow( rowNumber ) );
	}
	/**
	 * Determines if selected cells can be merged.
	 * 
	 * @return true if merge success, else false.
	 */
	public boolean canMerge( )
	{
		if ( !isActive() || isDelete( ) || getParent( ) == null )
		{