fix: keep editor writers at optimizer fixed point

Issue: #477
User-Visible: yes

src/draft-live-commit.ts

@@ -10,6 +10,7 @@ import {
 import { spacePhysicalGeometryFingerprint } from './plan-geometry-preflight';
 import {
   isSinglePartitionAppend, wallChainLiveCandidateSpace, wallChainLiveSeed,
+  type WallChainLiveSeed,
 } from './draft-live-preflight';
 
 const NORM_W = 1000;
@@ -34,7 +35,10 @@ export interface WallChainLiveCommitRuntime<
   Violation,
 > {
   host: WallChainLiveHost<State, Geometry>;
-  _commitPhysicalGeometry: (name: string, before: State | null) => boolean;
+  _commitPhysicalGeometry: (
+    name: string, before: State | null,
+    additionalAuthoredPoints?: readonly (readonly number[])[], recordHistory?: boolean,
+  ) => boolean;
   _clearGeometryGesture: () => void;
   _restoreGeometryStateInConfig: (config: ServerConfig, state: State) => boolean;
   _restoreGeometryStateLocal: (state: State) => boolean;
@@ -48,6 +52,88 @@ export interface WallChainLiveCommitRuntime<
   _saveConfig: () => void;
 }
 
+/**
+ * #477 finish transaction for a chain which has already been normalised on a
+ * clone.  It uses the same production physical/junction proof as a terminal
+ * click, centred on the pre-normalisation seed.  Unlike a click it records no
+ * extra history command: all segment commands already exist.
+ */
+export function commitWallChainFinishGeometry<
+  State extends { spaceId: string },
+  Geometry extends JunctionSharedGeometry,
+  Violation,
+>(
+  runtime: WallChainLiveCommitRuntime<State, Geometry, Violation>,
+  name: string,
+  before: State | null,
+  seed: WallChainLiveSeed | null,
+): boolean {
+  const { host } = runtime;
+  const liveCandidate = host._serverCfg;
+  const fallback = () => runtime._commitPhysicalGeometry(name, before, [], false);
+  if (!before || !liveCandidate || !seed
+      || Number(liveCandidate.model_version || 0) !== WALL_SEGMENT_MODEL_VERSION) return fallback();
+
+  let committedCandidate: ServerConfig;
+  try {
+    committedCandidate = commitWallSegmentModel(liveCandidate).config;
+  } catch (error) {
+    runtime._clearGeometryGesture();
+    runtime._restoreGeometryStateLocal(before);
+    runtime._showWallModelMigrationBlocked(error);
+    return false;
+  }
+  const committedSpace = committedCandidate.spaces.find((space) => space.id === before.spaceId);
+  const previousConfig = JSON.parse(JSON.stringify(liveCandidate)) as ServerConfig;
+  if (!committedSpace || !runtime._restoreGeometryStateInConfig(previousConfig, before)) {
+    return fallback();
+  }
+  const previousSpace = previousConfig.spaces.find((space) => space.id === before.spaceId);
+  const candidateProjection = wallChainLiveCandidateSpace(committedSpace, seed);
+  const previousProjection = wallChainLiveCandidateSpace(previousSpace, seed);
+  if (!candidateProjection || !previousProjection) return fallback();
+  const localCandidate = {
+    ...committedCandidate, spaces: [candidateProjection.space],
+  } as unknown as ServerConfig;
+  const localPrevious = {
+    ...previousConfig, spaces: [previousProjection.space],
+  } as unknown as ServerConfig;
+
+  let geometry: Geometry | null = null;
+  let safe = false;
+  try {
+    const authoredPoints = host._path.length >= 2
+      ? host._path.map((point) => [point[0] / NORM_W, point[1] / NORM_W]) : [];
+    safe = wallModelOffGridValueCount(committedSpace)
+      <= wallModelOffGridValueCount(before, authoredPoints)
+      && host._checkSpacePhysicalGeometry(
+        localCandidate, before.spaceId, (value) => { geometry = value; },
+      ).ok;
+  } catch {
+    safe = false;
+  }
+  if (!safe) return rejectUnsafe(runtime, before);
+  const introduced = runtime._junctionLimitsIntroduced(
+    localCandidate, localPrevious, before.spaceId, geometry, candidateProjection.roomIds,
+  );
+  if (introduced.length) {
+    runtime._clearGeometryGesture();
+    runtime._restoreGeometryStateLocal(before);
+    host._showToast(runtime._junctionLimitLabel(introduced[0]));
+    return false;
+  }
+
+  adoptWallSegmentModelCandidateInPlace(liveCandidate, committedCandidate);
+  const acceptedSpace = liveCandidate.spaces.find((space) => space.id === before.spaceId);
+  const pending = host._pendingPhysicalWrites.get(before.spaceId);
+  host._pendingPhysicalWrites.set(before.spaceId, {
+    before: pending?.before || before,
+    fingerprint: spacePhysicalGeometryFingerprint(acceptedSpace),
+  });
+  runtime._saveConfig();
+  return true;
+}
+
 const rejectUnsafe = <State extends { spaceId: string }, Geometry extends JunctionSharedGeometry,
   Violation>(runtime: WallChainLiveCommitRuntime<State, Geometry, Violation>, before: State): false => {
   runtime._clearGeometryGesture();