bpo-37451: remove redundant code in _testcapimodule.c

[shihai1991]

https://bugs.python.org/issue37451

[mangrisano]

Hi. Thank you for the pull request. I'm not an expert, therefore, would you mind telling me why that is redundant? Just for learning. Thank you :)

[jdemeyer]

I don't see why this code should be removed. It seems to be used for testing that PyUnicode_FromWideChar can deal with NULL-terminated and non-NULL-terminated buffers.

So at least, this PR needs better justification.

[shihai1991]

I don't see why this code should be removed. It seems to be used for testing that PyUnicode_FromWideChar can deal with NULL-terminated and non-NULL-terminated buffers.

So at least, this PR needs better justification.

Jeroen, thanks for review.

PyUnicode_FromWideChar can return two kind of values of three scenarios:

1. widechar_size + 1 if buffer is NULL or buflen > widechar_size + 1
   1.1 buffer is NULL can not happen in PyUnicode_FromWideChar because it have been judged in
   https://github.com/python/cpython/blob/master/Modules/_testcapimodule.c#L1852
   1.2 buflen > widechar_size + 1 is judged in _testcapimodule.c is ok.
2. buflen
   2.1 the latest return value is buflen or size(buflen==size) because of
   https://github.com/python/cpython/blob/master/Objects/unicodeobject.c#L3164.

So I think the else statement in _testcapimodule.c is redundant.

[shihai1991]

Hi. Thank you for the pull request. I'm not an expert, therefore, would you mind telling me why that is redundant? Just for learning. Thank you :)

Hi, Michele. Discussing process over result ;). I have answered upstairs.

[jdemeyer]

OK, I see what you mean now. But given that it took me a while to understand why your PR was correct, I'm not convinced that we should merge it as-is.

[shihai1991]

OK, I see what you mean now. But given that it took me a while to understand why your PR was correct, I'm not convinced that we should merge it as-is.

it's a small change and don't effect any functions, if core teams think it is not necessary, pls help me close this PR.
Don't waste too much time on it ;)

[zhangyangyu]

Thanks for the contribution and I could understand your logic. It actually is from my point of view but it's quite tiny and doesn't affect anything so I think it's not necessary to change it.