avl_tree: fixed FindPointer if on last node

git-svn-id: trunk@19728 -

packages/fcl-base/src/avl_tree.pp

@@ -791,7 +791,8 @@ begin
   while (Result<>nil) do begin
     if Result.Data=Data then break;
     Result:=FindSuccessor(Result);
-    if fOnCompare(Data,Result.Data)<>0 then Result:=nil;
+    if Result=nil then exit;
+    if fOnCompare(Data,Result.Data)<>0 then exit(nil);
   end;
 end;