Resolves: fdo#59183 Copy 4 or more slides then crash

regression from 17afe4cea7e01aef1e5270cc09f438bc6fde3211 which is totally
forgivable as its riddled with asserts that suggest there should be no
out-of-bounds accesses and there probably shouldn't and those queries are
possibly bugs. But double-checking 3-6 it is the case that non-existant pages
were queried for in that version too, so return NULL on out-of-bounds
like the original pre-stl conversion code did.

Change-Id: Ic918419b6cb76b083de6b6911dde9d6e00258324
(cherry picked from commit 63de2b8f1493f24669c78df3bc2d48d13528bd9f)
Reviewed-on: https://gerrit.libreoffice.org/1726
Reviewed-by: Noel Power <noel.power@suse.com>
Tested-by: Noel Power <noel.power@suse.com>

0 files changed, 0 insertions, 0 deletions