Filter: Implemented ::hasModifications to detect command line modifications

src/Filter.cpp

@@ -198,6 +198,16 @@ void Filter::subset (std::vector <Task>& output, bool applyContext /* = true */)
   context.timer_filter.stop ();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+bool Filter::hasModifications ()
+{
+  for (auto& a : context.cli2._args)
+    if (a.hasTag ("MODIFICATION"))
+      return true;
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // If the filter contains no 'or', 'xor' or 'not' operators, and only includes
 // status values 'pending', 'waiting' or 'recurring', then the filter is