tdf#125215 Assertion when closing Database/Advanced Settings

This showed up as a segfault for me.

Sometimes we have sortable items, for which we store duplicates (because
those items are not poolable), in which case comparing by operator==
means that we sometimes end up deleting the wrong one.

Change-Id: Ic7dff0357d3c5a7a74bf0b4e87fa02f2f5857f30
Reviewed-on: https://gerrit.libreoffice.org/72222
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

svl/source/inc/poolio.hxx

@@ -133,7 +133,8 @@ public:
                     assert(false && "did not find item?");
                     break;
                 }
-                if (**sortIt == *pNeedle)
+                // need to compare by pointer here, since we might have duplicates
+                if (*sortIt == pNeedle)
                 {
                     maSortablePoolItems.erase(sortIt);
                     break;
@@ -141,7 +142,7 @@ public:
                 ++sortIt;
             }
         }
-        return maPoolItemSet.erase(it);
+        maPoolItemSet.erase(it);
     }
 };