Related: #i17171# identify places where -1 was cast to 0xFFFF in the past

try and do so anyway. Could be picking that sort of lint out of writer
for a while to come :-(

(cherry picked from commit 16c565461b40c6876e69dc7bcc18f7c4db7fb94d)

Note: this fixes fdo#80571

Note: for backport, removed any changes where the variables are still
xub_StrLen; only sal_Int32 variables may have values < 0.

Signed-off-by: Michael Stahl <mstahl@redhat.com>

Conflicts:
	sw/source/core/crsr/swcrsr.cxx
	sw/source/core/text/porfld.cxx
	sw/source/core/text/txthyph.cxx
	sw/source/core/txtnode/fntcap.cxx
	sw/source/core/txtnode/txtedt.cxx

Change-Id: I4efb94e5ed33025f7f416c096af25ba358ef45af