m_nEndPos==m_nStartPos is OK: empty window (for example, empty table)
m_nEndPos==m_nStartPos is OK: empty window (for example, empty table)

Change-Id: I5525eb750dfbed282fea272de4a736e6c70e51a9

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core