Introduce a `SubViewportContainer` config for drag-and-drop targets

With the drag-and-drop rewrite, `SubViewportContainer` nodes were no
longer available as drop-locations.

This PR introduces a configuration option, that allows
`SubViewportContainer` to be considered as drop-location, but disables the
`Control` nodes inside its `SubViewport` children as drop-location.

1 files changed, 8 insertions, 0 deletions

diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index e70407f36e..9b27a28831 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -3062,6 +3062,14 @@ void Viewport::_update_mouse_over(Vector2 p_pos) {
 			}
 			v->_update_mouse_over(v->get_final_transform().affine_inverse().xform(pos));
 		}
+
+		Viewport *section_root = get_section_root_viewport();
+		if (section_root && c->is_consume_drag_and_drop_enabled()) {
+			// Evaluating `consume_drag_and_drop` and adjusting target_control needs to happen
+			// after `_update_mouse_over` in the SubViewports, because otherwise physics picking
+			// would not work inside SubViewports.
+			section_root->gui.target_control = over;
+		}
 	}
 }