On Wed, Dec 18, 2019 at 1:29 PM Junio C Hamano <gitster@xxxxxxxxx> wrote:
>
> "Elijah Newren via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
>
...
> > while (len && path[len - 1] == '/')
> > len--;
> > if (!len)
> > return 1;
> > +
> > + de = xcalloc(1, sizeof(struct dirent)+len+1);
>
> That "+len+1" may deserve a comment?
Good point, I'll add one and send a re-roll.
> If we wanted to shoot for the
> minimum memory consumption (and we do not), we would probably
> allocate
>
> (sizeof(struct dirent) - sizeof(de->d_name)) +
> max(sizeof(de->d_name), len + 1)
>
> bytes, but unconditionally adding len+1 is simpler and easier to
> understand. Either way, we *are* relying on the assumption that
> either:
>
> (1) the "struct dirent" would have d_name[] array at the end of the
> struct, and by over-allocating, we can safely fit and carry a
> name that is much longer than sizeof(.d_name[]); OR
>
> (2) the "struct dirent" has d_name[] that is large enough to hold len+1
> bytes, if the assumption (1) does not hold.
>
> is true.
>
> > + memset(&cdir, 0, sizeof(cdir));
> > + cdir.de = de;
> > +#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
> > + de->d_type = DT_DIR;
> > +#endif
> > baselen = 0;
> > + prevlen = 0;
> > while (1) {
> > - cp = path + baselen + !!baselen;
> > + prevlen = baselen + !!baselen;
> > + cp = path + prevlen;
> > cp = memchr(cp, '/', path + len - cp);
> > if (!cp)
> > baselen = len;
> > else
> > baselen = cp - path;
> > - strbuf_setlen(&sb, 0);
> > + strbuf_reset(&sb);
> > strbuf_add(&sb, path, baselen);
> > if (!is_directory(sb.buf))
> > break;
>
>
>
> > - if (simplify_away(sb.buf, sb.len, pathspec))
> > - break;
> > - if (treat_one_path(dir, NULL, istate, &sb, baselen, pathspec,
> > - DT_DIR, NULL) == path_none)
> > + strbuf_reset(&sb);
> > + strbuf_add(&sb, path, prevlen);
> > + memcpy(de->d_name, path+prevlen, baselen-prevlen);
> > + de->d_name[baselen-prevlen] = '\0';
> > + state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen,
> > + pathspec);
>
> So this is the crux fo the fix---instead of doing a (poor) imitation
> of what treat_path() does by calling simplify_away() and
> treat_one_path() ourselves, we make a call to the real thing.
>
> Looking good. Thanks.
