Problem:
A mapping that ends mid-operation (`nnoremap ,D d`) emits a content-free
"mapping" atom plus a `pending` field, and the "continuation" motion
arrives as a sibling atom. Consumers must stitch the two together (which
has broken cases, e.g. Insert-opening mappings (",i") lose their session
entirely).
- ",i": the session atom is dropped bc the mapping RHS is consumed
before the session starts (typebuf_maplen()==0), so
atom_is_user_input()=false.
- ":normal"-in-opfunc: the opfunc internal "v..y" session (a) became
kVatomTyped just because the deferred composite was open, masking the
real operator capture via atom_captures, and (b) its nested frames
re-derived the outer redo.
- "Motion" based on `moved=true`, has false negatives.
- `CmdAtom.remap` is unnecessary, and clutters the docs/usage.
Solution:
- Introduce `frame_id` to identify CmdFrames.
- Classify `type=motion` better, via `NV_MOTION` flag on the `nv_cmds` table.
- Drop `CmdAtom.pending`, `CmdAtom.remap`.
- Defer atom_composite_end() at the clock edge while an operator is
pending, Visual is active, or `restart_edit` is set: the composite
keeps collecting, so the continuation is captured in the mapping atom.
- ",i": Now an open composite counts as user input.
- ":normal"-in-opfunc: Now handled correctly.
- `remap` is now decided by `composite.payload || 0 subatoms`.
atom_payload_mark() records the read the resolution never captures.
- `toplevel` is now decided by `CmdFrame.parent == NULL`.
before/after:
INPUT BEFORE AFTER
---------------------------------------------------------------------
,D w {mapping lhs=,D pending=operator} {operator lhs=,Dw keys=dw}
+ {operator keys=dw}
ysiw" {mapping lhs=ys pending=operator} {operator lhs=ysiw" keys=g@iw"}
+ {operator lhs=g@iw"}
,v d {mapping pending=visual} {visual lhs=,vd keys=viwd}
+ {visual lhs=viwd}
,i XY<Esc> {normal keys=i lhs=,iXY<Esc>} {insert keys=1iXY<Esc> text=XY}