cid#1676285 Improper use of negative value

and

cid#1676283 Argument cannot be negative

Change-Id: I0096d15eb76f1e481a5c3a3ea8f69385c8eed93a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/196109
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>
Tested-by: Jenkins

sw/source/ui/dbui/customizeaddresslistdialog.cxx

@@ -121,7 +121,7 @@ IMPL_LINK_NOARG(SwCustomizeAddressListDialog, DeleteHdl_Impl, weld::Button&, voi
 IMPL_LINK(SwCustomizeAddressListDialog, UpDownHdl_Impl, weld::Button&, rButton, void)
 {
     auto nPos = m_xFieldsLB->get_selected_index();
-    assert(nPos && "nothing selected");
+    assert(nPos != -1 && "nothing selected");
     auto nOldPos = nPos;
     OUString aTemp = m_xFieldsLB->get_text(nPos);
     m_xFieldsLB->remove(nPos);

sw/source/uibase/utlui/glbltree.cxx

@@ -398,6 +398,12 @@ void SwGlobalTree::MoveSelectionTo(const weld::TreeIter* pDropEntry)
 {
     int nSource = m_xTreeView->get_selected_index();
 
+    if (nSource == -1)
+    {
+        SAL_WARN("sw", "No selection to move");
+        return;
+    }
+
     int nDest = pDropEntry ? m_xTreeView->get_iter_index_in_parent(*pDropEntry)
                            : m_pSwGlblDocContents->size();