puzzling behaviour of `info` at end of index

[Benno Schulenberg]

Hi,

For years I've been puzzled by what `info` does when it reaches the 
the end of an Index node: it seems to randomly jump back into the 
document.  Some months ago I finally understood what it does, which 
is what it always does: jump to the first menu entry.  This is fine 
when moving sequentially through a document, but not when reaching 
its end.  Imagine flipping through a book, reaching the last page, 
and then suddenly the flipping continues from somewhere in the 
middle: the flipping never ends.

When an info document doesn't contain an index, scrolling through it 
stops at the end.  So when a document _does contain an index, 
scrolling should also stop at the end.  An Index node should suspend 
the normal end-of-node behaviour of scroll-forward.

Maybe this behaviour could be controlled by a variable, say 
'at-end-of-index', with the following possible values: 
"stop" (default), "to-first-entry" (traditional), or "to-top-node".  
The latter value is probably what I would prefer to use: it would 
give a very quick way to reach the index: just hit scroll-backward 
when at the top node.

Benno