root window.size_changed is not emitted when Stretch Mode is set to "viewport" about godot HOT 2 CLOSED

if stretch mode (display/window/stretch/mode) is set to viewport, the root window (get_tree().root) will not emit its size_changed signal.

This only happens when display/window/stretch/mode is set to viewport and display/window/stretch/aspect is set to ignore or keep (but I assume this also happens with keep_width/keep_height when the height/width isn't being changed). When aspect is set to expand, the size_changed signal will be emitted when the window is resized through the window manager.

only happens to the root window

This does also happen for child windows with the same attributes, although both components of the content_scale_size vector need to be non-zero, otherwise the viewport will be resized. Also, setting content_scale_size on a window will emit the size_changed signal, even with the attributes set as above.

I'm wondering if this is technically a bug or if it's actually "working as intended" since the stretch mode tooltip mentions that "the size of the root Viewport is set precisely to the base size" and "finally, this viewport is scaled to fit the screen", so I guess the base size (I assume that means content_scale_size) of the viewport never really changes when the aspect ratio is kept. But the size attribute changes, so it would make sense that the size_changed signal is emitted, unless it really is only supposed to emit when the base size is changed, but then there should be two signals imo, size_changed for the size and content_scale_size_changed for the content_scale_size.

EDIT: I just saw that this is probably a duplicate of #79336

from godot.

Thanks for the report! Consolidating in godotengine/godot-proposals#8788, as this is intended behavior (the viewport size does not actually change when resizing the window). Therefore, implementing a notification for this is feature proposal territory.

from godot.