[AD] About the last config routine bug

["Eric Botcazou" <ebotcazou@xxxxxxxxxx>]

Bug #445078 on SourceForge's tracker (also reported by C. Graham on [AL]).

The problem can be restated as follows: the prettify_section_name() function
has got the property that fof=f (functional notation) except for the NULL
section: f(NULL)=EMPTY_STRING and f(EMPTY_STRING)="[]".

N. Abing proposes to extend the common behaviour to the NULL section (very
simple fix) by setting f(EMPTY_STRING)=EMPTY_STRING. The only drawback is
this ends up merging the NULL section and the [] section, i.e
get_config_*(NULL, name, def) == get_config_*(EMPTY_STRING, name, def).
(Is it really a drawback ?)

The other solution is to make sure that prettify_section_name() is always
called once on each passed section string (this was probably the original
behaviour, before the addition of hook functions to the code). I don't know
if this is easily feasible.

Any preference ?