check annotation caption pointers, blind fix for rhbz#1242099
check annotation caption pointers, blind fix for rhbz#1242099

Apparently there may have been situations when the caption or its shape
could not be obtained for whatever reason.

Change-Id: Ie9b97d4b3999cb4645bb6b8b688b3666cfd71ccc

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