[Rpm-maint] [rpm-software-management/rpm] debugedit: Distinguish files from directories in src list file (#1436)

[Mark Wielaard]

Hi,

On Sun, 2020-11-15 at 07:20 -0800, Vitalio wrote:
> Append '/' to directories in source file list (for `-l'
> option) to allow
> quickly distinguish them from regular files (to avoid adding them raw
> into %files section). This is needed for ALT for our debuginfo
> processing to speed things up.

I understand you would like to make sure all comp_dirs end with a
trailing '/' character. But I don't think unconditionally adding a '/'
is the right thing to do:

> diff --git a/tools/debugedit.c b/tools/debugedit.c
> index c2884933c..2eb912c72 100644
> --- a/tools/debugedit.c
> +++ b/tools/debugedit.c
> @@ -1923,7 +1923,7 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase)
>        const char *p = skip_dir_prefix (comp_dir, base_dir);
>        if (p != NULL && p[0] != '\0')
>          {
> -	  size_t size = strlen (p) + 1;
> +	  size_t size = strlen (p);
>  	  while (size > 0)
>  	    {
>  	      ssize_t ret = write (list_file_fd, p, size);
> @@ -1932,6 +1932,10 @@ edit_attributes (DSO *dso, unsigned char *ptr, struct abbrev_tag *t, int phase)
>  	      size -= ret;
>  	      p += ret;
>  	    }
> +	  /* Output trailing dir separator to distinguish them quickly from
> +	     regular files. */
> +	  if (size == 0)
> +	    write (list_file_fd, "/", 2);
>  	}
>      }

Note for others, the list_file contains zero terminated file names.
That is why we want to write size = strlen (p) + 1 characters, so that
it includes the '\0' terminator.

After the while loop size is always zero, unless an error occurred and
not all characters were written. So this code would add a "/"
(including a termination '\0') always, even if there was already one.
So I think you actually want to test that p[0] != '/' before adding the
string "/", but just write (list_file_fd, "", 1) otherwise.

BTW. How does this help you speed things up?

Cheers,

Mark