Variables with wrong types become 0 instead of being cast correctly

[kb173]

Say I have the following function in a GDExtension project:

void Example::print_variables(double double_val, int int_val) {
	UtilityFunctions::print(double_val, " and ", int_val);
}

As expected, calling example.print_variables(123.0, 321) from GDScript prints "123 and 321" to the console.

However, when the types do not match (e.g. mixing up float and int), they are not properly cast automatically: the debugger does print a warning like Narrowing conversion (float is converted to int and loses precision), but the output is not still "123 and 321" as I would expect. Rather, the variable with the false type is simply 0.

Example: calling example.print_variables(123, 321) (first argument is now int rather than float) produces "0 and 321" in the console.

This type of bug is really hard to track down in a reasonably complex project, so I would expect either a full error if the types don't match, or a better automatic conversion.

Here's a minimal reproduction (just a quick modification of the example project from this repo): type-cast-repro.zip running it in Godot shows that, as described above, parameters with wrong types simply become 0. This is the case even if Godot's optional static typing is not used (= rather than :=).

Tested in Godot 4.0 Beta 3

[Skwint]

I just ran into the exact same thing. Passing const radius = 10 to a C++ set_radius(real_t p_radius); and it gets a value of 0 with no warnings or errors. It should definitely cast it. GDscript does allow you to strongly type a variable but I don't think anyone expects to have to!

[DmitriySalnikov]

In fact, values are not always converted to 0.
If you convert floating point numbers that are less than 0, then you get nan.
But if the native function accept, for example, Vector2i, and GDScript pass Vector2(-50, 50) as an argument, then the native function will get Vector2i(-1035468800, 1112014848).

[dsnopek]

This sounds like it may be a duplicate of godotengine/godot#75757

Can you test if PR godotengine/godot#75758 fixes it for you?