[PATCH 0/4] allow more sources for config values

> The idea to allow more kinds of sources specified for "config_file"
> structure is not bad per-se, but whenever you design an enhancement
> to something that currently supports only on thing to allow taking
> another kind, please consider what needs to be done by the next
> person who adds the third kind.  That would help catch design
> mistakes early.  For example, will the "string-list" (I am not
> saying use of string-list makes sense as the third kind; just as an
> example off the top of my head) source patch add
> 
> 	int is_string_list;
>         struct string_list *string_list_contents;
> 
> fields to this structure?  Sounds insane for at least two reasons:
> 
>  * if both is_strbuf and is_string_list are true, what should
>    happen?
> 
>  * is there a good reason to waste storage for the three fields your
>    patch adds when sring_list strage (or FILE * storage for that
>    matter) is used?
> 
> The helper functions like config_fgetc() and config_ftell() sounds
> like you are going in the right direction but may want to do the
> OO-in-C in a similar way transport.c does, keeping a pointer to a
> structure of methods, but I didn't read the remainder of this patch
> very carefully enough to comment further.