Subject: Re: [PATCH 1/3] unpack: replace xwrite() loop with write_in_full()

From: Junio C Hamano <[email-masked]>
Date: Mon, 04 Mar 2024 08:43:03 -0800

Junio C Hamano <[email-masked]> writes:

> Patrick Steinhardt <[email-masked]> writes:
>
>>> -		while (input_len) {
>>> -			err = xwrite(1, input_buffer + input_offset, input_len);
>>> -			if (err <= 0)
>>> -				break;
>>> -			input_len -= err;
>>> -			input_offset += err;
>>> -		}
>>> +		/* Write the last part of the buffer to stdout */
>>> +		write_in_full(1, input_buffer + input_offset, input_len);
>>
>> With this change we stop updating `input_len` and `input_offset`, both
>> of which are global variables. Assuming that tests pass this must be
>> okay right now given that this is the final part of what we are writing.
>> But I wonder whether we shouldn't update those regardless just so that
>> these remain consistent?
>
> It is probably a good hygiene, even though it may not matter at all
> for the correctness in the current code.
>
> Thanks for your sharp eyes.

Actually, I changed my mind.  As you said, this is flushing the very
end of the data in the input_buffer[] and nobody will fill() the
input_buffer[] after the call to this function happens.

>>> -	while (len) {
>>> ...
>>> -		len -= ret;
>>> -		offset += ret;
>>> -	}
>>> +	write_in_full(1, buffer + offset, len);
>>
>> Same here.

Ditto.  We are about to pass the control back to the caller that
will exit using the "has_errors" we return from here.

>> Patrick
>>>  	/* All done */
>>>  	return has_errors;
>>> -- 
>>> 2.44.0-84-gb387623c12