External Tools get filtered-out lines in their $(CurText) input

If I have defined an External Tool that takes “Custom” input, and then define this custom input as “$(CurText)”, there is a bug that sends also any filtered-out lines inside the selectiong as input to this External Tool when multiple lines are selected.

For example, if you have the following lines in your document:

111
222
333
444

And then I create a filter that removes all lines containing “222” and “333”, resulting in the following appearance in the editor:

111
444

If I now select both these lines, and then execute my External Tool, it will still get all the four lines as input (i.e. “111”, “222”, “333” and “444”), which seems like an obvious bug to me, right?