tdf#150241: a blind fix attempt

I can't repro it locally (the report misses clear repro steps), but
the three changed OUString assignment operators use rtl::str::assign
internally, and the unconditional dereference of the value returned
from SwDoc::GetDocPattern (that may return a nullptr) is suspicious,
especially compared to the checks made in SwDocStyleSheet::GetHelpId
later in the same file.

All four calls to GetDocPattern in the file were introduced in commit
7b0b5cdfeed656b279bc32cd929630d5fc25878b
Author Jens-Heiner Rechtien <hr@openoffice.org>
Date   Mon Sep 18 16:15:01 2000 +0000
initial import

Change-Id: If9d4cff921443e5af71b7d541b79d00ea77e853b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/137734
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

0 files changed, 0 insertions, 0 deletions