caller appears to report wrong line when block passed and brackets omitted #5949

Dear mruby developers,

I've recently started working with mruby and am busy porting my codebase from cruby to mruby in such a way that the code executes the same. Its been throwing up a lot of issues (mostly due to occasional missing methods), which I am managing to get past. However, some of my tests are failing due to the following issue. The following code demonstrates the problem. I heavily use the second form (without the function call brackets) so this issue is important to me. I also heavily rely on Kernel#caller. This issue only shows up if a block is passed aswell as not using brackets. Is this a bug? It definitely behaves different to cruby which does what I expect.

Thanks for mruby!

def a(id) = puts caller[0]

a(1) do # caller reports this line
end

a 1 do
end # without brackets caller reports this line