Re: [PATCH] poke: Prefer ${XDG_CONFIG_HOME:-$HOME/.config} to XDG_CONFIG_DIRS

[Jose E. Marchesi]

Hello.

Thank you very much for the patch.
I just pushed it to master on your behalf.

> Some DEs (namely, KDE) set the latter without setting $XDG_CONFIG_HOME,
> because the XDG specification says:
>
>     Specifications may reference this specification by specifying the
>     location of a configuration file as
>     $XDG_CONFIG_DIRS/subdir/filename. This implies that:
>
>     ...
>     - A user-specific version of the configuration file may be created
>       in $XDG_CONFIG_HOME/subdir/filename, taking into account the
>       default value for $XDG_CONFIG_HOME if $XDG_CONFIG_HOME is not set.
>     ...
>
> It is implied (and also followed by other programs) that the default
> value of XDG_CONFIG_HOME should be preferred to $XDG_CONFIG_DIRS, even
> when the former is not set but the latter is. This also seems to be in
> the spirit of the standard, which treats XDG_CONFIG_HOME as a writable
> location (so, the program can modify it in accordance with the users
> wishes), while treating XDG_CONFIG_DIRS as read only locations, normally
> for default values or distro-provided overrides.
>
> 2022-09-24  Arsen Arsenović   <arsen@aarsen.me>
>
>       * poke/poke.c: Prefer $XDG_CONFIG_HOME to $XDG_CONFIG_DIRS, even
>       when unset.
> ---
> Hey there,
>
> This is the fix for the minor bug I noticed today while in the BBB meeting.
>
> An implementation note: I chose to strdup () the getenv () result, so that it
> can be validly freed (normally, freeing a getenv result is at least UB) over
> carrying a "should free" value. This is slightly simpler, avoids a GCC warning
> about discarding const, and shouldn't have much of an impact, since it's early
> in the startup procedure.
>
> Thanks in advance!
>
>  poke/poke.c | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/poke/poke.c b/poke/poke.c
> index b3849664..7b258410 100644
> --- a/poke/poke.c
> +++ b/poke/poke.c
> @@ -698,16 +698,31 @@ initialize_user (void)
>       use all the : separated paths in that variable to find
>       pokerc.conf.  Else, try to load /etc/xdg/poke/pokerc.conf.  */
>    {
> -    const char *xdg_config_home = getenv ("XDG_CONFIG_HOME");
> +    char *xdg_config_home = getenv ("XDG_CONFIG_HOME");
>      const char *xdg_config_dirs = getenv ("XDG_CONFIG_DIRS");
>  
>      if (xdg_config_home == NULL)
> -      xdg_config_home = "";
> +      {
> +        /* If unset, the default value of $HOME/.config should be preferred 
> to
> +           the paths in $XDG_CONFIG_DIRS. From the standard:
> +
> +           A user-specific version of the configuration file may be created 
> in
> +           $XDG_CONFIG_HOME/subdir/filename, taking into account the default
> +           value for $XDG_CONFIG_HOME if $XDG_CONFIG_HOME is not set. */
> +        xdg_config_home = pk_str_concat (getenv("HOME"), "/.config", NULL);
> +        pk_assert_alloc (xdg_config_home);
> +      }
> +    else
> +      {
> +        /* strdup() the user-provided value, to free it below. */
> +        xdg_config_home = strdup(xdg_config_home);
> +        pk_assert_alloc (xdg_config_home);
> +      }
>  
>      if (xdg_config_dirs == NULL)
>        xdg_config_dirs = "/etc/xdg";
>  
> -    char *config_path = pk_str_concat (xdg_config_dirs, ":", 
> xdg_config_home, NULL);
> +    char *config_path = pk_str_concat (xdg_config_home, ":", 
> xdg_config_dirs, NULL);
>      pk_assert_alloc (config_path);
>  
>      char *dir = strtok (config_path, ":");
> @@ -736,6 +751,7 @@ initialize_user (void)
>      while ((dir = strtok (NULL, ":")) != NULL);
>  
>      free (config_path);
> +    free (xdg_config_home);
>    }
>  }