bug#9528: 24.0.50; Info navigation

[Juri Linkov]

>> >> >> 1. Eval: (info "(elisp)Macros")
>> >> >> 2. Move point to line 22 (* Simple Macro).
>> >> >> 3. Type: <DEL>
>> >> >>  --> (Expected) Go to node "(elisp)Related Topics".
>> >> >>  --> (Observed) Go to node "(elisp)Simple Macro".
>> >> >
>> >> > Sorry, I can't change this because this behavior is explicitly
>> >> > implemented in Info, so it's not a bug.
>> >
>> > I think it's a bug, because the stand-alone Info reader goes to
>> > Related Topics.
>>
>> I agree that it looks like a bug, but I don't understand why it's coded
>> explicitly that way.  Perhaps the intention was to implement this behavior
>> only when the value of `Info-scroll-prefer-subnodes' is non-nil?
>
> Maybe, I cannot say.  We can condition it on that variable.

Yes, this behavior is documented in the docstring of `Info-scroll-down':
"If point is within the menu of a node, and `Info-scroll-prefer-subnodes'
 is non-nil, this goes to its last subnode."

So I fixed it to work according to the docstring.