bug#20466: 25.0.50; REGRESSION in `isearch-mode-map': <backspace> is not translated to DEL

[Stefan Monnier]

> The "why" part was answered by Artur, who pointed to the bug report
> which triggered that change.
[...]
> I learned long ago that if you want to change the binding of DEL, you
> had better changed the binding of Backspace accordingly at the same time,

I strongly disagree here: following this kind of rule is what caused the
problem in the first place.

What you're basically saying is that we should give up on the
function-key-map binding which remaps `backspace' to DEL.

Clearly, this bug report shows that this remapping is harder to handle
right in the case of isearch-mode-map.

I think The Right Way to handle it is to bind (in isearch-mode-map)
`backspace' to `undefined' (so it hides bindings in lower-precedence
maps, but still lets the function-key-map remapping take place).


        Stefan