classname:_init is inherited exactly one level and that is confusing

[mcclure]

I am a longtime user of Penlight, I make especially heavy use of the class module.

I found something today. I check out a copy of Penlight 1.6.0. I run lua5.1 and run the following:

> class = require("pl.class")
> class.A()
> function A:_init(x) print(x) end
> A(3)
3
> class.B(A)
> B(4)
4
> class.C(B)
> C(5)
> 

B inherits from A, C inherits from B. Only A has an explicit constructor. B inherits A's constructor, but C does not inherit a constructor.
This feels like a bug, it's not in the documentation. In my testing, methods other than _init can be implicitly inherited multiple levels deep without problems.

My expected behavior is that if I don't override the constructor, it should be inherited as many levels deep as the hierarchy goes.

[mcclure]

Looking at the class.lua code, the problem seems to be that call_ctor() walks all the way up the chain looking for a _init to call, but mt.__call explicitly checks only rawget(c,'_init') and rawget(base,'_init') and then gives up.

Is there some reason _init could not be "fat inherited" into the class object the same way methods are?

[alerque]

Is there any progress on including this? I just spent quite a while bashing my head against an issue that turns out to have it's root in my expectation of this exact things being fixed.