From: Jeff King <peff@peff.net>
Date: Thu, 07 Dec 2017 21:28:55 GMT
Subject: Re: [PATCH] strbuf: release memory on read error in strbuf_read_once()
Message-ID: <20171207212855.GE12850@sigill.intra.peff.net>
In-Reply-To: <6a39662f-8ff2-c314-5348-4189737a6853@web.de>

On Thu, Dec 07, 2017 at 09:51:26PM +0100, René Scharfe wrote:

> If other strbuf add functions cause the first allocation and
> subsequently encounter an error then they release the memory, restoring
> the pristine state of the strbuf.  That simplifies error handling for
> callers.
> 
> Do the same in strbuf_read_once(), and do it also in case no bytes were
> read -- which may or may not be an error as well, depending on the
> caller.

Makes sense, and the patch is delightfully simple.

For the "0" case nobody should be negatively impacted by dropping the
allocation, as they get a sane 0-length string from the slopbuf (and
anybody who relies on sb->buf being allocated without calling detach or
similar is already doing it wrong).

-Peff