fix(gateway): preserve partial transcript branches

CHANGELOG.md

@@ -49,6 +49,7 @@ Docs: https://docs.openclaw.ai
 - Config persistence: strip malformed pending final-delivery session fields on load so replay/recovery paths skip poisoned reply metadata instead of crashing on raw objects.
 - Config persistence: strip malformed plugin extension state and promoted session-slot ownership on load so corrupted session rows do not leak poisoned plugin metadata into replay/projection paths.
 - Gateway/sessions: ignore malformed compaction checkpoint rows during session projection so corrupted stores do not crash session list/describe responses or show bogus checkpoint counts.
+- Gateway/sessions: keep reachable transcript history when imported tree transcripts reference missing or legacy parent rows, preventing session history reads from going empty after a partial import.
 - Providers: reject malformed successful Runway, BytePlus, and Ollama embedding responses with provider-owned errors instead of raw parser/type failures, silent bad vectors, or long bogus polling.
 - Providers/images: reject malformed successful OpenAI-compatible, OpenAI, Google, fal, and OpenRouter image responses with provider-owned errors instead of raw shape failures, silent invalid base64 skips, or empty image results.
 - Providers/videos: reject malformed successful xAI, OpenRouter, and fal video create, poll, and result responses with provider-owned errors instead of raw parser failures or long bogus polling.

src/gateway/session-transcript-index.fs.ts

@@ -146,7 +146,7 @@ function buildActiveTreeEntries(params: {
     seen.add(currentId);
     const entry = params.byId.get(currentId);
     if (!entry) {
-      return [];
+      break;
     }
     out.push(entry);
     currentId = entry.parentId ?? undefined;
@@ -206,10 +206,12 @@ async function buildSessionTranscriptIndex(
       record: parsed,
     };
     rawEntries.push(rawEntry);
-    if (isTreeTranscriptRecord(parsed) && id) {
-      hasTreeEntries = true;
-      leafId = id;
+    if (id) {
       byId.set(id, rawEntry);
+      if (isTreeTranscriptRecord(parsed)) {
+        hasTreeEntries = true;
+        leafId = id;
+      }
     }
   });
 

src/gateway/session-utils.fs.test.ts

@@ -886,6 +886,72 @@ describe("readSessionMessages", () => {
     }
   });
 
+  test("keeps async active branch rows when imported parent links are incomplete", async () => {
+    const sessionId = "test-session-tree-async-incomplete-parent";
+    writeTranscript(tmpDir, sessionId, [
+      { type: "session", version: 3, id: sessionId },
+      {
+        type: "message",
+        id: "legacy-user",
+        message: { role: "user", content: "legacy prompt" },
+      },
+      {
+        type: "message",
+        id: "tree-assistant",
+        parentId: "legacy-user",
+        message: { role: "assistant", content: "tree reply" },
+      },
+      {
+        type: "message",
+        id: "orphan-tail",
+        parentId: "missing-imported-parent",
+        message: { role: "assistant", content: "reachable orphan tail" },
+      },
+    ]);
+    clearSessionTranscriptIndexCache();
+
+    const messages = await readSessionMessagesAsync(sessionId, storePath, undefined, {
+      mode: "full",
+      reason: "test imported partial tree selection",
+    });
+
+    expect(messages.map((message) => (message as { content?: unknown }).content)).toEqual([
+      "reachable orphan tail",
+    ]);
+    expectMessageFields(messages[0], { openclaw: { id: "orphan-tail", seq: 1 } });
+  });
+
+  test("keeps legacy async parents when tree transcripts reference pre-v3 rows", async () => {
+    const sessionId = "test-session-tree-async-legacy-parent";
+    writeTranscript(tmpDir, sessionId, [
+      { type: "session", version: 1, id: sessionId },
+      {
+        type: "message",
+        id: "legacy-user",
+        message: { role: "user", content: "legacy hello" },
+      },
+      {
+        type: "message",
+        id: "tree-assistant",
+        parentId: "legacy-user",
+        message: { role: "assistant", content: "tree hello" },
+      },
+    ]);
+    clearSessionTranscriptIndexCache();
+
+    const messages = await readSessionMessagesAsync(sessionId, storePath, undefined, {
+      mode: "full",
+      reason: "test legacy parent active tree selection",
+    });
+
+    expect(messages.map((message) => (message as { content?: unknown }).content)).toEqual([
+      "legacy hello",
+      "tree hello",
+    ]);
+    expectMessageFields(messages[0], { openclaw: { id: "legacy-user", seq: 1 } });
+    expectMessageFields(messages[1], { openclaw: { id: "tree-assistant", seq: 2 } });
+  });
+
   test("caches async transcript indexes by file stats", async () => {
     const sessionId = "test-session-index-cache";
     writeTranscript(tmpDir, sessionId, [