Created attachment 242620 [details]
Generated C code

Executing the included code on e.g. armhf, the assertion fails. If I explicitly cast the uint64 to int in the generated code, it works there.

nemequ suggested as a work-around on IRC to use an unowned temporary variable, which works as well.

class Foo : Object {
	public signal void available(uint8[] data);

	public void run() {
		Timeout.add_seconds (1, () => {
			uint64 length = 65536;
			var data = new uint8[65537];

			this.available(data[0:length]);

			return false;
		});
	}
}

class Bar : Object {
	public Bar(Foo foo) {
		foo.available.connect((data) => {
			assert (data.length == 65536);
		});
	}
}

int main (string[] args)
{
	var foo = new Foo();
	var bar = new Bar(foo);
	foo.run();
	var loop = new MainLoop(null, false);
	loop.run();
	return 0;
}