"(abc)|(def)" matches "def" with result offset sequences
{0,-1,0},{3,-1,3}

And thus the assert() calls introduced with
4cf1d290 and
ce91f3c1 were hit.

Change-Id: I571b6c7d47349a2cc7b1d1e34193b2865012a49f
(cherry picked from commit 4dd2d406)
Reviewed-on: https://gerrit.libreoffice.org/20174Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mikekaganski@hotmail.com>
(cherry picked from commit a38963a4)