Catch missing self argument in overloads constructor

[rhaschke]

The following unittest code was segfaulting due to missing self argument in call to __init__

class BrokenTF6(m.TestFactory6):
    def __init__(self):
        m.TestFactory6.__init__()

Fixed now, by catching this edge case and throwing an appropriate exception.

Suggested changelog entry:

Catch a missing ``self`` argument in calls to ``__init__()``.

[henryiii]

This looks like a good idea to me.

[henryiii]

Could you please re-add the changlog entry to the issue description? Those get auto-processed into the changelog draft.

[rhaschke]

@henryiii, I added a changelog suggestion. Hope this is in line with the desired verbosity and formatting.

[henryiii]

Formatting gets auto applied (bullets and periods if missing), and I can tweak it, but it helps to have a starting point. Thanks! (I will change it to be RST though ;) )

[YannickJadoul]

Huh, how has this never been seen/caught before!?

Good catch, @rhaschke!

[henryiii]

Probably because the normal way to call this is with super, and there you have to supply self (or it gets automatically picked up in Python 3).

[YannickJadoul]

Probably because the normal way to call this is with super, and there you have to supply self (or it gets automatically picked up in Python 3).

Hmmm, though pybind11 actually explicitly warns not to use super, since it won't fit with the way multiple inheritance currently works.