[asterisk-dev] ast_category_root is the same as ast_variable_browse!

[Luigi Rizzo]

the two functions in main/config.c
ast_category_root() and ast_variable_browse() do the same thing: given
a config file and string representing a category name, both
return a pointer to the first variable in the category.

If there is a difference, it is that ast_variable_browse() has an
optimization (but probably a broken one) to avoid scanning the
list of categories on repeated searches: if you look at the
line marked "--->" below, the comparison is made just on the
pointer and not on the content of the string.

    struct ast_variable *ast_variable_browse(const struct ast_config *config, const char *category)
    {
        struct ast_category *cat = NULL;
                 
--->    if (category && config->last_browse && (config->last_browse->name == category))
                cat = config->last_browse;
        else    
                cat = ast_category_get(config, category);
                
        return (cat) ? cat->root : NULL;
    }

Given that there is no point for having two identical functions,
i would like to first remove ast_category_root() which is the least
used one (only one instance in chan_sip.c) and later have a look
again at the implementation of the cache
(config->last_browse) to at least document the behaviour and
verify if there is any ill side effect.

	cheers
	luigi