When loading ooo68143-1.sxw we get an assert:

Assertion `!(bListeningAlready && !bPreventDuplicates) && "duplicate
listener, try building with DBG_UTIL to find the other insert site."'

The connector is connected to the same SdrObject on both ends:

<draw:connector ...
 draw:start-shape="id13" draw:start-glue-point="2"
 draw:end-shape="id13" draw:end-glue-point="2">

Change-Id: Ia0dd140b7c2ca948ace3fbf93d8c4abd4331399d