From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 16 Dec 2007 19:43:28 GMT
Subject: Re: trim_common_tail bug?
Message-ID: <7v8x3ul927.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20071216070614.GA5072@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> On Sat, Dec 15, 2007 at 03:02:02PM -0500, Jeff King wrote:
>
>> >   	for (i = 0, recovered = 0; recovered < trimmed && i <= ctx; i++) {
>> > 		while (recovered < trimmed && ap[recovered++] != '\n')
>> > 	        	; /* nothing */
>> > 	}
>> > 
>> > then (warning: I haven't had my coffee yet)?
>> 
>> Yes, I think that is equivalent. My sleep-deprived brain keeps thinking
>> there must be a more clear way of writing this whole loop, but it
>> escapes me at the moment.
>
> And this came to me in a dream. :) It fixes the bug, and I think it is a
> bit simpler to see the termination conditions in a single loop. But
> please double-check correctness, and that you agree that it is more
> readable.

I wanted to recover to the end of the line that includes the cut-off
point, even when (ctx == 0), to be extra safer, but I do not think it
was necessary.

> ...
>  		bp -= blk;
>  	}
>  
> +	while (recovered < trimmed && ctx)
> +		if (ap[recovered++] == '\n')
> +			ctx--;
>  	a->size -= (trimmed - recovered);
>  	b->size -= (trimmed - recovered);
>  }