Outputting NFC with ibus-m17n

[Richard Wordingham]

I have a couple of problems using m17n with ibus on Ubuntu.

ibus 1.5.26-4
ibus-m17n 1.4.9-1
m17n-db 1.8.0-3

The core of the keyboard definition is a set of keystroke definitions
such as

(map
 (simple
;; cy3sn-p1:
  ("B"     ?β) ; U+03b2 GREEK SMALL LETTER BETA
...
  ("e_H"     ?é)     ; U+00E9 LATIN SMALL LETTER E WITH ACUTE
  ))
(state (init (simple)))

These problems didn't occur when I was using fcitx as the input method.

The first problem is that when the sequence of keystrokes is an initial
portion of another sequence of keystrokes, the character I thought I had
entered simply disappears after a while if I don't firm it up by moving
to another character, e.g. by entering more strokes or moving the
cursor.

The second problem is that the character I entered gets converted to
NFD.  Thus I can't enter e acute to grep for the line defining its
keystrokes - I have to create my own regular expression engine to do
searches respecting Unicode canonical equivalence.

Am I missing some tricks to avoid these problems?  The idea of the
keyboard is that I can just type IPA by typing XSAMPA.

Richard.