Re: [bug-patch] [PATCH] do not validate target name when it is specified on the command line

[Jim Meyering]

Andreas Gruenbacher wrote:
> On Wednesday 16 February 2011 18:03:21 Jim Meyering wrote:
>> Here's a better patch.
>
> Nice.  Now we can suppress warnings for equal filenames too for even fewer
> confusing warnings.  Here is your last patch + some coding style changes +
> actually comparing filenames + test case.

Good improvements.  I usually put a space between the "!!" operator
and its operand, too.

I noticed that we can avoid a useless comparison in the common case,
(i.e., if bad[0] is NULL, there's no point in testing bad[1])
but am not sure it's worth the addition of three lines and loss
of symmetry:

  if (bad[0])
    {
      if (! strcmp (bad[0], name))
        return false;
      if (bad[1] && ! strcmp (bad[1], name))
        return false;
    }


> diff --git a/src/pch.c b/src/pch.c
> index 41c15b6..1fd3848 100644
> --- a/src/pch.c
> +++ b/src/pch.c
> @@ -379,11 +379,18 @@ skip_hex_digits (char const *str)
>  static bool
>  name_is_valid (char const *name)
>  {
> -  const char *n = name;
> +  static char const *bad[2];
> +  char const *n;
> +
> +  if (bad[0] && ! strcmp (bad[0], name))
> +    return false;
> +  if (bad[1] && ! strcmp (bad[1], name))
> +    return false;
>
>    if (IS_ABSOLUTE_FILE_NAME (name))
>      {
>        say ("Ignoring potentially dangerous file name %s\n", quotearg (name));
> +      bad[!! bad[0]] = name;
>        return false;
>      }
>    for (n = name; *n; )
> @@ -391,6 +398,7 @@ name_is_valid (char const *name)
>        if (*n == '.' && *++n == '.' && ( ! *++n || ISSLASH (*n)))
>          {
>         say ("Ignoring potentially dangerous file name %s\n", quotearg 
> (name));
> +       bad[!! bad[0]] = name;
>         return false;
>       }
>        while (*n && ! ISSLASH (*n))