Add size check in Control::_edit_set_state() to fix crash

[sps1112]

fixes #46017
add size check to prevent crash when executing Control.new()._edit_set_state({})

[KoBeWi]

This method will also crash when the passed Dictionary is missing any of the used keys, e.g. Control.new()._edit_set_state({"test": 1}) will still crash.

So to fix this properly, you'd have to add a check for each existence of each key. I wonder if it's worth it though, the method isn't visible in documentation. It's mean for internal use only (see godotengine/godot-proposals#2285) and we didn't have crash reports from editor usage (and even if we had, the error doesn't help much as it still needs to be fixed).

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 3.2.4.

[akien-mga]

Reverted with 372b1b8 (and undid cherry-pick before pushing) as the change is wrong:

ERROR: Condition "(p_state.size() <= 0) || p_state["rotation"].is_null() || p_state["scale"].is_null() || p_state["pivot"].is_null() || p_state["anchors"].is_null() || p_state["offsets"].is_null()" is true.
   at: _edit_set_state (scene/gui/control.cpp:76)

Variant::is_null() checks if the Variant is a null Object, that's not the right way to validate the existence of dictionary keys.

Try to move any Control, this change spams:

ERROR: Condition "(p_state.size() <= 0) || p_state["rotation"].is_null() || p_state["scale"].is_null() || p_state["pivot"].is_null() || p_state["anchors"].is_null() || p_state["offsets"].is_null()" is true.
   at: _edit_set_state (scene/gui/control.cpp:76)

[KoBeWi]

Right, I didn't test it in the editor before approving and was surprised it works .-.

This should be p_state.has("rotation") etc.