forcepoint #31 check validity of another group range

Change-Id: I82ff3e47a033c91581b108e1685b1ff4d5865895
Reviewed-on: https://gerrit.libreoffice.org/51881Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sc/source/core/data/column3.cxx

@@ -3120,6 +3120,8 @@ public:
             {
                 // Previous cell is a regular cell and current cell is a group.
                 nRow += xCurGrp->mnLength;
+                if (xCurGrp->mnLength > std::distance(it, itEnd))
+                    throw css::lang::IllegalArgumentException();
                 std::advance(it, xCurGrp->mnLength);
                 pPrev->SetCellGroup(xCurGrp);
                 xCurGrp->mpTopCell = pPrev;