An IBus client throws away a dead key its engine did not take — the GTK
module's own comment says so, and Qt does the same — so é and ü were
lost in every IBus application, while XIM composed them with a table of
its own. That table moves to compose.c, which both frontends now use;
xim.c is the shorter for it.
A finished sequence is text, not a key: the engine is asked to hand back
what it had pending, and the composed text follows it, so the composed
character can no longer land before the syllable typed before it.
Cclientpreedit was a one-bit mask that every producer set as "want ?
Cclientpreedit : 0" and every consumer masked out again; nothing else
was ever going to join it. Keyreq carries clientpre, an int that says
whether the client draws the preedit, and the engine and the XIM
context keep it under that name.
An XIM spot has no height, so a popup that flips above it at the bottom
of the screen ended on the baseline and covered the line being typed.
The spot now stands for the row above it, one popup row tall, as GTK
and IBus carets carry their line height; below the spot nothing moves.
win.c and xim.c each iterated the setup's roots to find the screen
xcb_connect had chosen; xcb-util, already linked through imdkit, has
xcb_aux_get_screen for that.
A Compose sequence whose result is more than one character has no
keysym, so xkb_compose_state_get_one_sym gave nothing and the result was
lost; the UTF-8 the compose state holds is committed instead. Clients
that ask for a StatusNone style — fcitx5 offers them — failed to create
an input context; the three preedit styles come in both status flavours
now. IBus SetCursorLocation returned an error for a negative width or
height that nothing reads and no client ever waits for.
xim/keymap.c held one 37-line function apart from xim.c, with its own
prototype typed by hand in xim.c and nelem spelt out because it avoided
dat.h — all so that a test could link it without imdkit, though the XIM
adapter test #includes xim.c whole anyway. It lives in xim.c now, and
xim.c, the last file of its directory, sits beside ibus.c.