bug#6387: 24.0.50; ESC TAB should be bound to `isearch-complete'

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> I wonder why `ESC C-i' works in isearch, but `ESC TAB' doesn't work.
> (There is no special key binding for `ESC C-i' in isearch.)

It probably has to do with the fact that isearch uses default-bindings
(i.e. bindings to the event gt which stands for "any event").
Such bindings prevent function-key-map (and similar hardcoded key
translations such as A -> a, S-left -> left, double-mouse-1 -> mouse-1,
...) from doing its job (since function-key-map is only used if the
untranslated sequence has no bindings which never happens thanks to the
default binding which always applies).

I've tried to change read-key-sequence such that a default binding is
only applied *after* function-key-map (or at least that a default
binding does not prevent function-key-map translations), but so far this
has failed.


        Stefan