Re: [PATCH] Change mutt_buffer_concatn_path() to use fixed algorithm.

Alejandro Colomar via Mutt-dev <[email protected]> Tue, 19 May 2026 12:15:20 +0200
Newsgroups	gmane.mail.mutt.devel
Message-ID	<agw3r9HJQDjyY6qs@devuan>
Hi Kvein,

On 2026-05-19T13:56:45+0800, Kevin J. McCarthy wrote:
> Revise it to use mutt_buffer_concat_path(), which was fixed in commit
> 048f4ae2.
> ---
> 
> Derek Martin noticed this function was using an incorrect algorithm too.
> 
> The function is only called in one place, mutt_complete() which handles
> command prompt completion of path.
> 
> *** This commit, however does cause a CHANGE OF BEHAVIOR. ***
> 
> When the dir part is empty, the old algorithm concatn_path combines:
>   "" + "dir" => "dir"
> 
> The new algorithm, now using mutt_buffer_concat_path, combines:
>   "" + "dir" => "/dir"
> 
> To see the change in mutt, start up mutt and
>   - :unset folder<enter>
>   - <change-folder>
>   - At the prompt: Open mailbox ('?' for list):
>     =usr/
>     then hit Tab twice.
> 
> Before this commit mutt will try to expand "usr" in your cwd.
> After this commit mutt will try to expand "/usr".

Doesn't = mean it's a relative path?  Is it correct to interpret it as
/usr?  I'm not very familiar with how these paths work, so I might be
completely wrong.


Have a lovely day!
Alex

> 
> You can also see the difference if you start mutt from your homedir, and
> subsitute "usr/" for a directory in your homedir, such as "Documents/".
> 
> This is an edge case, but I wanted to bring it up for discussion before
> making this change.
> 
>  muttlib.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/muttlib.c b/muttlib.c
> index baef6038..df882002 100644
> --- a/muttlib.c
> +++ b/muttlib.c
> @@ -1421,19 +1421,25 @@ void mutt_buffer_concat_path(BUFFER *d, const char *dir, const char *fname)
>  }
>  
>  /*
> - * Write the concatened pathname (dir + "/" + fname) into dst.
> - * The slash is omitted when dir or fname is of 0 length.
> + * Write the concatened pathname (dir + "/" + fname) into dst,
> + * respecting the size limits passed in.
>   */
>  void mutt_buffer_concatn_path(BUFFER *dst, const char *dir, size_t dirlen,
>                                const char *fname, size_t fnamelen)
>  {
> -  mutt_buffer_clear(dst);
> +  BUFFER *dirbuf, *fnamebuf;
> +
> +  dirbuf = mutt_buffer_pool_get();
> +  fnamebuf = mutt_buffer_pool_get();
> +
>    if (dirlen)
> -    mutt_buffer_addstr_n(dst, dir, dirlen);
> -  if (dirlen && fnamelen)
> -    mutt_buffer_addch(dst, '/');
> +    mutt_buffer_addstr_n(dirbuf, dir, dirlen);
>    if (fnamelen)
> -    mutt_buffer_addstr_n(dst, fname, fnamelen);
> +    mutt_buffer_addstr_n(fnamebuf, fname, fnamelen);
> +  mutt_buffer_concat_path(dst, mutt_b2s(dirbuf), mutt_b2s(fnamebuf));
> +
> +  mutt_buffer_pool_release(&dirbuf);
> +  mutt_buffer_pool_release(&fnamebuf);
>  }
>  
>  const char *mutt_getcwd(BUFFER *cwd)
> -- 
> 2.54.0
> 

-- 
<https://www.alejandro-colomar.es>
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