Re: [PATCH] setup_revisions(): take pathspec from command line and --stdin correctly

[Thiago Farina <tfransosi@gmail.com>]

On Wed, May 11, 2011 at 6:44 PM, Junio C Hamano <gitster@pobox.com> wrote:
> When the command line has "--" disambiguator, we take the remainder of
> argv[] as "prune_data", but when --stdin is given at the same time, we
> need to append to the existing prune_data and end up attempting to
> realloc(3) it, which would not work and can lead to a segfault or worse.
>
> Fix it by consistently using append_prune_data() throughout the input
> processing.  Also avoid counting the number of existing paths in the
> function over and over again.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>
>  * This is relative to 1.6.6; the bug originates back to 60da8b1 (Make
>   --stdin option to "log" family read also pathspecs, 2009-11-20).
>
>  revision.c                |   80 ++++++++++++++++-----------------------------
>  t/t6017-rev-list-stdin.sh |   17 +++++++++
>  2 files changed, 45 insertions(+), 52 deletions(-)
>
> diff --git a/revision.c b/revision.c
> index c92ffc2..58b5651 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -956,35 +956,34 @@ int handle_revision_arg(const char *arg, struct rev_info *revs,
>        return 0;
>  }
>
> -static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb, const char ***prune_data)
> -{
> -       const char **prune = *prune_data;
> -       int prune_nr;
> -       int prune_alloc;
> +struct cmdline_pathspec {
Maybe prune_data_pathspec?

> +       int alloc;
> +       int nr;
> +       const char **path;
> +};
>
> -       /* count existing ones */
> -       if (!prune)
> -               prune_nr = 0;
> -       else
> -               for (prune_nr = 0; prune[prune_nr]; prune_nr++)
> -                       ;
> -       prune_alloc = prune_nr; /* not really, but we do not know */
> +static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
av is the same thing as argv? If so, is it worth naming it argv? I
know the old was av, so maybe not though.

> +{
> +       while (*av) {
> +               ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
I'd add spaces between prune->nr + 1. But I think is fine as is too.

> +               prune->path[prune->nr++] = *(av++);
> +       }
> +}
>
> +static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
> +                                    struct cmdline_pathspec *prune)
> +{
>        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
>                int len = sb->len;
>                if (len && sb->buf[len - 1] == '\n')
>                        sb->buf[--len] = '\0';
> -               ALLOC_GROW(prune, prune_nr+1, prune_alloc);
> -               prune[prune_nr++] = xstrdup(sb->buf);
> +               ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
> +               prune->path[prune->nr++] = xstrdup(sb->buf);
>        }
> -       if (prune) {
> -               ALLOC_GROW(prune, prune_nr+1, prune_alloc);
> -               prune[prune_nr] = NULL;
> -       }
> -       *prune_data = prune;
>  }
>
> -static void read_revisions_from_stdin(struct rev_info *revs, const char ***prune)
> +static void read_revisions_from_stdin(struct rev_info *revs,
> +                                     struct cmdline_pathspec *prune)
>  {
>        struct strbuf sb;
>        int seen_dashdash = 0;
> @@ -1279,34 +1278,6 @@ static int for_each_good_bisect_ref(each_ref_fn fn, void *cb_data)
>        return for_each_ref_in("refs/bisect/good", fn, cb_data);
>  }
>
> -static void append_prune_data(const char ***prune_data, const char **av)
> -{
> -       const char **prune = *prune_data;
> -       int prune_nr;
> -       int prune_alloc;
> -
> -       if (!prune) {
> -               *prune_data = av;
> -               return;
> -       }
> -
> -       /* count existing ones */
> -       for (prune_nr = 0; prune[prune_nr]; prune_nr++)
> -               ;
> -       prune_alloc = prune_nr; /* not really, but we do not know */
> -
> -       while (*av) {
> -               ALLOC_GROW(prune, prune_nr+1, prune_alloc);
> -               prune[prune_nr++] = *av;
> -               av++;
> -       }
> -       if (prune) {
> -               ALLOC_GROW(prune, prune_nr+1, prune_alloc);
> -               prune[prune_nr] = NULL;
> -       }
> -       *prune_data = prune;
> -}
> -
>  /*
>  * Parse revision information, filling in the "rev_info" structure,
>  * and removing the used arguments from the argument list.
> @@ -1317,7 +1288,9 @@ static void append_prune_data(const char ***prune_data, const char **av)
>  int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
>  {
>        int i, flags, left, seen_dashdash, read_from_stdin;
> -       const char **prune_data = NULL;
> +       struct cmdline_pathspec prune_data;
> +
> +       memset(&prune_data, 0, sizeof(prune_data));
>
>        /* First, search for "--" */
>        seen_dashdash = 0;
> @@ -1328,7 +1301,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
>                argv[i] = NULL;
>                argc = i;
>                if (argv[i + 1])
> -                       prune_data = argv + i + 1;
> +                       append_prune_data(&prune_data, argv + i + 1);
>                seen_dashdash = 1;
>                break;
>        }
> @@ -1420,8 +1393,11 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
>                }
>        }
>
> -       if (prune_data)
> -               revs->prune_data = get_pathspec(revs->prefix, prune_data);
> +       if (prune_data.nr) {
> +               ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
> +               prune_data.path[prune_data.nr++] = NULL;
> +               revs->prune_data = get_pathspec(revs->prefix, prune_data.path);
> +       }
>
>        if (revs->def == NULL)
>                revs->def = def;
> diff --git a/t/t6017-rev-list-stdin.sh b/t/t6017-rev-list-stdin.sh
> index f1c32db..667b375 100755
> --- a/t/t6017-rev-list-stdin.sh
> +++ b/t/t6017-rev-list-stdin.sh
> @@ -58,4 +58,21 @@ check side-3 ^side-4 -- file-3
>  check side-3 ^side-2
>  check side-3 ^side-2 -- file-1
>
> +test_expect_success 'not only --stdin' '
> +       cat >expect <<-EOF &&
> +       7
> +
> +       file-1
> +       file-2
> +       EOF
> +       cat >input <<-EOF &&
> +       ^master^
> +       --
> +       file-2
> +       EOF
> +       git log --pretty=tformat:%s --name-only --stdin master -- file-1 \
> +               <input >actual &&
> +       test_cmp expect actual
> +'
> +
>  test_done
> --
> 1.7.5.1.315.ge7efa
>
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