bug#4147: 23.1.50: Info-search command strange behaviour

[Juri Linkov <juri@jurta.org>]

>>>>     s blahblah RET
>>>>     => Says it can't find it, but moves point forward a few characters.
>>
>> The odd behavior when point moves forward by a few characters
>> is caused by breadcrumbs inserted to the Info buffer (the distance
>> point moves forward is the length of the breadcrumbs string).
>
> To fix this one idea is to remove the breadcrumbs line on leaving
> from the node, so breadcrumbs in all nodes located above the current
> node will not affect the point position.  And in the case of getting
> the current point position, subtract the length of breadcrumbs in
> the current node.

Another idea I've considered is using point positions relative to the
beginning of the node.  But to be able to fix this for Isearch in Info
we have to change semantics of Isearch variables like `isearch-other-end',
to use relative point positions.  This is too much trouble too.

The only sane way I see to fix this problem is:

1. not to insert breadcrumbs to the Info buffer;

2. display breadcrumbs in the header line;

3. not to hide next/prev/up navigation links in the first line
   of the node.

`Info-use-header-line' could provide an additional value `breadcrumbs'
that does this and set it by default.

If this is acceptable, I can prepare a patch.

-- 
Juri Linkov
http://www.jurta.org/emacs/