From: Eric Sunshine <sunshine@sunshineco.com>
Date: Sun, 29 Sep 2013 19:26:45 GMT
Subject: Re: [PATCH 6/9] http: update base URLs when we see redirects
Message-ID: <CAPig+cQVQ6iY8onvb--88W0XHofC815NZHTb=L744hANtT8mVQ@mail.gmail.com>
In-Reply-To: <20130928083405.GA2782@sigill.intra.peff.net>

On Sat, Sep 28, 2013 at 4:34 AM, Jeff King <peff@peff.net> wrote:
> diff --git a/http.c b/http.c
> index 65a0048..8775b5c 100644
> --- a/http.c
> +++ b/http.c
> @@ -921,11 +921,71 @@ static int http_request_reauth(const char *url,
> +static int update_url_from_redirect(struct strbuf *base,
> +                                   const char *asked,
> +                                   const struct strbuf *got)
> +{
> +       const char *tail;
> +       size_t tail_len;
> +
> +       if (!strcmp(asked, got->buf))
> +               return 0;
> +
> +       if (strncmp(asked, base->buf, base->len))
> +               die("BUG: update_url_from_redirect: %s is not a superset of %s",
> +                   asked, base->buf);

Is there something non-obvious going on here? die(...,base->buf) takes
advantage of the terminating NUL promised by strbuf, but then
strncmp(...,base->buf,base->len) is used rather than the simpler
strcmp(...,base->buf).

> +       tail = asked + base->len;
> +       tail_len = strlen(tail);
> +
> +       if (got->len < tail_len ||
> +           strcmp(tail, got->buf + got->len - tail_len))
> +               return 0; /* insane redirect scheme */
> +
> +       strbuf_reset(base);
> +       strbuf_add(base, got->buf, got->len - tail_len);
> +       return 1;
> +}