sw: avoid EXCEPTION_INT_DIVIDE_BY_ZERO
See https://crashreport.libreoffice.org/stats/signature/SwFormatCol::Calc(unsigned%20short,unsigned%20short)
Change-Id: I79321737b7bed3acff3418d0b51dc6225baaf57f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/135184
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>
Tested-by: Xisco Fauli <xiscofauli@libreoffice.org>
(cherry picked from commit
ea4cd397300120a0f825752182eb3b943eb8a1b2)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/135254
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>
(cherry picked from commit
6bbc42687b795b6279b1b96bb721991f90eca4da)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/135259
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>
Tested-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>