safe STRING_NOTFOUND -> -1 conversion
safe STRING_NOTFOUND -> -1 conversion

Change-Id: Id66b9ff49289d90f2d0714bed84e886598f103ad

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