v2.2.2-xml-placeholder-reject: drop placeholder XML tool calls at parse time

Reject qwen3.6 spurious <invoke> tails with path "..." or empty args before
they enter toolCalls, preventing duplicate assistant answers. Dropped blocks
append to flushed text; four new xml-parser tests. DEFERRED-WORK §6 for
console.debug → pino cleanup.

Co-authored-by: Cursor <cursoragent@cursor.com>

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes per release tag. Most recent on top, ordered by tag creation date (which matches the git history). Tag names follow `vMAJOR.MINOR.PATCH-slug` — the slug describes what shipped, so the tag name alone is enough to recall the batch.
 
+## v2.2.2-xml-placeholder-reject — 2026-05-26
+
+Reject placeholder XML tool args at parse time in `extractToolCallBlocks` (`xml-parser.ts`). Drops calls when any string arg is `...`, empty/whitespace, `<path>`, `<file>`, `placeholder`, or angle-bracket sentinels; appends the raw XML block to flushed prose instead of silently deleting it. Fixes qwen3.6 answer-then-spurious-tools tail that caused duplicate assistant rows (full answer + failed `xml_call_*` tools + regenerated answer). Four new tests in `xml-parser.test.ts`. Known nit: rejection logs via `console.debug` instead of pino — filed in `docs/DEFERRED-WORK.md` §6 for a later cleanup.
+
 ## v2.2.1-pane-scoped-chats — 2026-05-26
 
 Follow-up fixes on the v2.2 Paseo provider stack. Pane-scoped chat resolution: `resolveChatId(sql, sessionId, paneId)` reads `sessions.workspace_panes`, requires `pane_id` on coder POST routes, and creates a scoped chat per coder/terminal pane instead of falling back to the session's first open chat (which fused BooCoder writes into the BooChat pane). Client `useWorkspacePanes` seeds new coder/terminal panes with dedicated chats on create, hydrate, and workspace sync; `CoderPane` blocks send until seeded and filters WS frames + `GET /messages?chat_id=` to that chat. External-agent tool UI: new `CoderMessageList` renders BooChat-style `ToolCallLine` timeline (tools before answer text on combined ACP rows). WS user-delta handling replaces content instead of appending (fixes garbled duplicate user messages when optimistic UI met full-body deltas). BooChat inference: `buildMessagesPayload` strips orphan assistant `tool_calls` without matching `tool` rows and skips stray tool rows when the owning assistant turn is incomplete (fixes "Tool results are missing for tool calls" on shared chats with ACP history). Pairs with `v2.2-paseo-providers`.

CURRENT.md

@@ -5,6 +5,6 @@ Last updated: 2026-05-26
 - **Batch:** v2.3-provider-lifecycle (openspec drafted; not started)
 - **Branch:** `main`
 - **Blockers:** none
-- **Last shipped:** `v2.2.1-pane-scoped-chats` (pairs with `v2.2-paseo-providers` on same commit)
+- **Last shipped:** `v2.2.2-xml-placeholder-reject`
 
 Update this file when starting or finishing a batch. Agents: read this first for session intent; if stale vs `CHANGELOG.md`, trust CHANGELOG for shipped state.

apps/server/src/services/__tests__/xml-parser.test.ts

@@ -270,6 +270,44 @@ describe('extractToolCallBlocks (v1.13.16 — unified extraction)', () => {
     expect(result.flushed).toBe(input);
     expect(result.remaining).toBe('');
   });
+
+  describe('placeholder arg rejection (qwen3.6 answer-then-spurious-tools)', () => {
+    it('rejects <invoke> with path "..." — 0 calls, block in flushed', () => {
+      const block = '<invoke name="view_file"><parameter name="path">...</parameter></invoke>';
+      const result = extractToolCallBlocks(`Answer text.\n${block}`);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toContain('Answer text.');
+      expect(result.flushed).toContain(block);
+      expect(result.remaining).toBe('');
+    });
+
+    it('rejects <invoke> with empty path — 0 calls, block in flushed', () => {
+      const block = '<invoke name="view_file"><parameter name="path"></parameter></invoke>';
+      const result = extractToolCallBlocks(block);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toBe(block);
+      expect(result.remaining).toBe('');
+    });
+
+    it('rejects <invoke> with path "<path>" — 0 calls', () => {
+      const block = '<invoke name="view_file"><parameter name="path"><path></parameter></invoke>';
+      const result = extractToolCallBlocks(block);
+      expect(result.calls).toEqual([]);
+      expect(result.flushed).toBe(block);
+    });
+
+    it('returns 1 valid call and flushes placeholder block when mixed in same buffer', () => {
+      const valid =
+        '<invoke name="view_file"><parameter name="path">/opt/boocode/README.md</parameter></invoke>';
+      const placeholder =
+        '<invoke name="view_file"><parameter name="path">...</parameter></invoke>';
+      const result = extractToolCallBlocks(`${valid} tail ${placeholder}`);
+      expect(result.calls).toEqual([{ name: 'view_file', args: { path: '/opt/boocode/README.md' } }]);
+      expect(result.flushed).toContain('tail');
+      expect(result.flushed).toContain(placeholder);
+      expect(result.remaining).toBe('');
+    });
+  });
 });
 
 describe('levenshtein', () => {

apps/server/src/services/inference/xml-parser.ts

@@ -24,6 +24,34 @@ export interface ParsedCall {
   args: Record<string, unknown>;
 }
 
+const PLACEHOLDER_LITERALS = new Set(['...', 'placeholder', '<path>', '<file>']);
+const ANGLE_BRACKET_SENTINEL_RE = /^<[^>]+>$/;
+
+/** True when a string arg looks like a model placeholder, not a real path/value. */
+export function isPlaceholderArgValue(value: unknown): boolean {
+  if (typeof value !== 'string') return false;
+  const trimmed = value.trim();
+  if (trimmed === '') return true;
+  if (PLACEHOLDER_LITERALS.has(trimmed)) return true;
+  if (ANGLE_BRACKET_SENTINEL_RE.test(trimmed)) return true;
+  return false;
+}
+
+function hasPlaceholderArgs(args: Record<string, unknown>): boolean {
+  for (const value of Object.values(args)) {
+    if (isPlaceholderArgValue(value)) return true;
+  }
+  return false;
+}
+
+function logRejectedPlaceholder(parsed: ParsedCall): void {
+  // Pure helper — no Fastify logger here (stream-phase.ts stays unchanged).
+  console.debug(
+    { toolName: parsed.name, args: parsed.args },
+    'rejected placeholder tool call at parse time',
+  );
+}
+
 // v1.10.5: Qwen-flavor parser. Tightened in v1.13.16 to tolerate whitespace
 // around `=` (e.g. `<function = view_file>`). Name capture is non-whitespace,
 // non-`>` so a stray space doesn't get absorbed into the function name.
@@ -152,7 +180,14 @@ export function extractToolCallBlocks(buffer: string): ToolCallExtraction {
     const blockEnd = next.closeIdx + next.spec.close.length;
     const block = buffer.slice(next.openIdx, blockEnd);
     const parsed = next.spec.parse(block);
-    if (parsed) calls.push(parsed);
+    if (parsed) {
+      if (hasPlaceholderArgs(parsed.args)) {
+        logRejectedPlaceholder(parsed);
+        flushed += block;
+      } else {
+        calls.push(parsed);
+      }
+    }
     pos = blockEnd;
   }
 

docs/DEFERRED-WORK.md

@@ -15,6 +15,7 @@ Last updated: 2026-05-26
 | Unified `packages/types` | Maintainability | Low (dev-only) | Medium–High | Type drift between server, coder, web |
 | Large file splits | Maintainability | None directly | Medium per file | Harder reviews, merge conflicts |
 | Retire `apps/coder/web/` fallback SPA | Scope / ops | Low — Sam uses CoderPane | Medium | Dual UI maintenance, divergent API client |
+| `console.debug` in xml-parser placeholder rejection | Maintainability | None (logs only) | Trivial | Placeholder rejections miss pino pipeline / level filters |
 
 ---
 
@@ -325,6 +326,16 @@ Standalone Vite React app (`@boocode/coder-web`) built into `apps/coder/web/dist
 
 ---
 
+## 6. xml-parser placeholder rejection — structured logging (v2.2.2 cleanup)
+
+**Shipped (uncommitted deploy):** `extractToolCallBlocks` rejects placeholder XML tool args at parse time; dropped blocks append to `flushed`.
+
+**Nit:** rejection path uses `console.debug` instead of the Fastify/pino `log.debug({ toolName, args }, '…')` pattern used elsewhere. Cosmetic — behavior is correct; logs won't appear in the usual structured pipeline or respect `LOG_LEVEL`.
+
+**Fix:** pass an optional logger into `extractToolCallBlocks` from `stream-phase.ts` executeStreamPhase (one call site), or use a module-level debug hook. Target tag: **v2.2.2** cleanup batch, not a blocker.
+
+---
+
 ## Suggested batch ordering
 
 If picking these up as openspec batches:
@@ -334,6 +345,7 @@ If picking these up as openspec batches:
 3. **CoderPane hook extraction** — natural follow-on when adding cancel UI
 4. **Zod parity or packages/types** — when next WS/provider field is added
 5. **Retire coder/web** — only after explicit “I don’t use :9502 UI” confirmation
+6. **v2.2.2 xml-parser log uniformity** — `console.debug` → pino (§6)
 
 ---