Dropping to Script Editor is broken if scrolling past end of file is enabled

[KoBeWi]

Godot version

3.5 beta3

System information

Windows 10 x64

Issue description

When you enable text_editor/cursor/scroll_past_end_of_file in editor settings and try to drop a file into the script, dragging over the area under the script will cause scrolling down and makes the editor unusable:

Does not happen on master.

Steps to reproduce

1. Enable scroll past end of file
2. Open some script that can scroll
3. Try dropping some file

Minimal reproduction project

No response

[akien-mga]

I can confirm the regression in 3.5 beta 2, 3.5 beta 3 and latest 3.x.
It doesn't happen in 3.4.4-stable or 3.5 beta 1, so the regression happened between beta 1 and beta 2.

[akien-mga]

I haven't tested but from reviewing the changelog I have a hunch that it might be because of #55355. CC @ConteZero

[ConteZero]

Yes, the problem is in the following code:

		if (drag_action && can_drop_data(mm->get_position(), get_viewport()->gui_get_drag_data())) {
			drag_caret_force_displayed = true;
			Point2 mp = get_local_mouse_position();
			int row, col;
			_get_mouse_pos(Point2i(mp.x, mp.y), row, col);
			cursor_set_line(row, true);
			cursor_set_column(col);
			if (row <= get_first_visible_line()) {
				_scroll_lines_up();
			} else if (row >= get_last_full_visible_line()) {
				_scroll_lines_down();
			}
			dragging_selection = true;
			update();
		}

But I don't know how to fix it.

[KoBeWi]

The easiest "fix" would be removing this part:

if (row <= get_first_visible_line()) {
	_scroll_lines_up();
} else if (row >= get_last_full_visible_line()) {
	_scroll_lines_down();
}

It would disable scrolling when dragging at the edges, but it's better than breaking the editor. From my experience, most dragging operations happen on a single screen.

[akien-mga]

Fixed by #61980.