fix(#496): keep the adopted thread anchor authoritative across DAP responses/events

CHANGELOG.md

@@ -27,6 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **`packageManager` pinned to pnpm@10.33.0** — a different pnpm major regenerated `pnpm-lock.yaml` incompatibly (one contributor diff silently dropped the entire security `overrides` block); the pin plus a CONTRIBUTING note make the wrong-pnpm case fail fast, and the workflows read the pin instead of duplicating a version (#478)
 
 ### Fixed
+- **An adopted thread anchor survives `list_threads` and follow-up inspection calls** — the anchor adopted by `get_stack_trace`'s frameless-thread fallback (or an explicit `get_stack_trace {threadId}`, #465) was silently reverted to the stale stopped-event thread by the functional-core state echo on the very next DAP response or event: `list_threads` clobbered it, and even the documented `threadId` recovery survived exactly one inspection call because that call's own response reverted it — so stack → threads → locals answered about the frameless thread and returned nothing. The echo no longer overwrites the live anchor (the imperative fast path is authoritative), and adoptions are mirrored into the functional-core snapshot so the two stores can't disagree again (#496)
 - **js breakpoints tell the truth about binding — attach and launch** — js-debug binds breakpoints in a child session while the parent answers with provisional stubs (`verified:false`, "Unbound breakpoint", parent-space ids), and nothing reconciled the two on the attach path: a breakpoint set after `attach_to_process` raced a fire-and-forget child mirror, and one set before attach stayed "Unbound breakpoint" with no adapterId forever — even after it demonstrably fired — because js-debug answers a no-change re-send with an empty echo and emits no late bind event for it. The proxy now hands the child's authoritative `setBreakpoints` response back through the sync path (marked child-sourced, bounded 3s wait), `attach_to_process` gains the post-launch belt-and-braces re-sync (with a clear+re-set to force a fresh echo for already-registered sets), and every previously-silent mirror failure mode logs. Child-origin `breakpoint` events are tagged at the proxy, so a late parent stub whose integer id collides with the stored child id can no longer downgrade a verified record by id-match, and parent-space/provisional-stub ids never enter the store (the #495 intermittent signature); `syncBreakpointsForFile` also normalizes raw l10n keys before storing, closing #471's last gap (#500, #495)
 - **Java attach to a `suspend=y` JVM no longer freezes the target permanently** — the #465 post-attach pause called `vm.suspend()` unconditionally, so a JVM launched with JDWP `suspend=y` (already at JDI suspend count 1) ended up at count 2 while `continue`'s single `vm.resume()` only took it back to 1: the first continue "succeeded" but nothing ever ran, breakpoints never fired, and the session was stuck. The bridge's pause is now idempotent — when every thread is already suspended it reports the stopped event without deepening the suspend count (same for the single-thread pause path), so one continue releases the VM; pausing a genuinely running VM is unchanged (regression from #483, #489)
 - **A typo'd attach `adapterConfig` key now gets a did-you-mean warning instead of silence** — every attach-capable adapter declares the attach keys its debugger actually consumes (`supportedAttachKeys`), and `attach_to_process` warns about keys outside that set with an edit-distance suggestion (`pathMapping (did you mean pathMappings?)`) while still **forwarding** them to the debug adapter untouched, so upstream debugger options the list doesn't model keep working with no mcp-debugger release; keys an adapter's transform genuinely drops keep warning as ignored (#450's contract). The javascript, ruby, java, and dotnet attach transforms also move from closed allowlists to the python/cpp deny-list pattern, so advanced attach options (js-debug's `localRoot`/`remoteRoot`/`sourceMaps`/`skipFiles`/`continueOnAttach`, rdbg's `localfsMap`, netcoredbg's `sourceFileMap`/`symbolOptions`) now genuinely reach the debugger. Thanks @abhijeetnardele24-hash for the `supportedAttachKeys` + did-you-mean design (#466)

src/proxy/proxy-manager.ts

@@ -18,7 +18,8 @@ import {
   DAPSessionState,
   addPendingRequest,
   removePendingRequest,
-  clearPendingRequests
+  clearPendingRequests,
+  setCurrentThreadId as setCoreCurrentThreadId
 } from '../dap-core/index.js';
 import type {
   ProxyStatusMessage,
@@ -571,6 +572,12 @@ export class ProxyManager extends EventEmitter implements IProxyManager {
 
   setCurrentThreadId(threadId: number): void {
     this.currentThreadId = threadId;
+    // Mirror into the functional-core snapshot so an adopted anchor (the
+    // frameless-thread fallback, get_stack_trace {threadId}) is not stale
+    // there (issue #496).
+    if (this.dapState) {
+      this.dapState = setCoreCurrentThreadId(this.dapState, threadId);
+    }
   }
 
   private async prepareSpawnContext(config: ProxyConfig): Promise<{
@@ -1030,12 +1037,10 @@ export class ProxyManager extends EventEmitter implements IProxyManager {
         // Sync local state with functional core state
         this.isInitialized = result.newState.initialized;
         this.adapterConfigured = result.newState.adapterConfigured;
-        // Only update currentThreadId if the core provided a concrete number.
-        // Avoid overwriting the value we set in the fast-path dapEvent handler with null/undefined.
-        const coreTid = (result.newState as { currentThreadId?: number | null }).currentThreadId;
-        if (typeof coreTid === 'number') {
-          this.currentThreadId = coreTid;
-        }
+        // The imperative currentThreadId is authoritative — the fast-path
+        // stopped handler in handleDapEvent writes it. Restoring the core's
+        // copy here clobbered anchors adopted via setCurrentThreadId() on
+        // every subsequent response/event (issue #496).
       }
 
       // Resolve/reject pending DAP request Promises. The functional core above only
@@ -1085,6 +1090,9 @@ export class ProxyManager extends EventEmitter implements IProxyManager {
           const first = threads.length ? threads[0]?.id : undefined;
           if (typeof first === 'number') {
             this.currentThreadId = first;
+            if (this.dapState) {
+              this.dapState = setCoreCurrentThreadId(this.dapState, first);
+            }
           }
         }
       } catch {

tests/unit/proxy/proxy-manager.start.test.ts

@@ -1340,6 +1340,112 @@ describe('ProxyManager.start', () => {
     expect(proxyManager.getCurrentThreadId()).toBe(12);
   });
 
+  // Issue #496: an anchor adopted via setCurrentThreadId() (the frameless-thread
+  // fallback and the get_stack_trace {threadId} path) must survive subsequent
+  // proxy messages — the functional-core state echo used to restore the stale
+  // stopped-event thread over it on every response and event.
+  describe('adopted thread anchor persistence (issue #496)', () => {
+    const primeStoppedOnThread1 = () => {
+      (proxyManager as unknown as { proxyProcess: IProxyProcess | null }).proxyProcess = fakeProcess;
+      (proxyManager as unknown as { isInitialized: boolean }).isInitialized = true;
+      (proxyManager as unknown as { sessionId: string | null }).sessionId = baseConfig.sessionId;
+      (proxyManager as unknown as { dapState: ReturnType<typeof createInitialState> | null }).dapState =
+        createInitialState(baseConfig.sessionId);
+
+      // The DAP-stopped thread reports no frames in the #496 scenario; the
+      // session layer then adopts a frame-bearing thread via setCurrentThreadId.
+      (proxyManager as unknown as {
+        handleProxyMessage: (message: object) => void;
+      }).handleProxyMessage({
+        type: 'dapEvent',
+        sessionId: baseConfig.sessionId,
+        event: 'stopped',
+        body: { threadId: 1, reason: 'pause' }
+      });
+      expect(proxyManager.getCurrentThreadId()).toBe(1);
+      // handleProxyMessage syncs isInitialized from the functional-core state,
+      // which this test primes as uninitialized — restore the flag.
+      (proxyManager as unknown as { isInitialized: boolean }).isInitialized = true;
+
+      proxyManager.setCurrentThreadId(2);
+      expect(proxyManager.getCurrentThreadId()).toBe(2);
+    };
+
+    const respondToDapWith = (body: object) => {
+      fakeProcess.sendCommand.mockImplementation((payload) => {
+        if (payload.cmd === 'dap') {
+          (proxyManager as unknown as {
+            handleProxyMessage: (message: object) => void;
+          }).handleProxyMessage({
+            type: 'dapResponse',
+            sessionId: baseConfig.sessionId,
+            requestId: payload.requestId,
+            success: true,
+            response: {
+              type: 'response',
+              seq: 21,
+              request_seq: 7,
+              command: payload.dapCommand,
+              success: true,
+              body
+            }
+          });
+        }
+      });
+    };
+
+    it('survives a threads response (list_threads)', async () => {
+      primeStoppedOnThread1();
+      respondToDapWith({ threads: [{ id: 1, name: 'main' }, { id: 2, name: 'worker' }] });
+
+      await proxyManager.sendDapRequest<any>('threads');
+
+      expect(proxyManager.getCurrentThreadId()).toBe(2);
+    });
+
+    it('survives an unrelated output event', () => {
+      primeStoppedOnThread1();
+
+      (proxyManager as unknown as {
+        handleProxyMessage: (message: object) => void;
+      }).handleProxyMessage({
+        type: 'dapEvent',
+        sessionId: baseConfig.sessionId,
+        event: 'output',
+        body: { category: 'stdout', output: 'hello\n' }
+      });
+
+      expect(proxyManager.getCurrentThreadId()).toBe(2);
+    });
+
+    it('survives a stackTrace response (anchor is not single-use)', async () => {
+      primeStoppedOnThread1();
+      respondToDapWith({
+        stackFrames: [{ id: 1000, name: 'main', line: 7, column: 1 }],
+        totalFrames: 1
+      });
+
+      await proxyManager.sendDapRequest<any>('stackTrace', { threadId: 2 });
+
+      expect(proxyManager.getCurrentThreadId()).toBe(2);
+    });
+
+    it('still re-anchors on a genuine stopped event', () => {
+      primeStoppedOnThread1();
+
+      (proxyManager as unknown as {
+        handleProxyMessage: (message: object) => void;
+      }).handleProxyMessage({
+        type: 'dapEvent',
+        sessionId: baseConfig.sessionId,
+        event: 'stopped',
+        body: { threadId: 7, reason: 'breakpoint' }
+      });
+
+      expect(proxyManager.getCurrentThreadId()).toBe(7);
+    });
+  });
+
   it('rejects DAP requests on proxy error', async () => {
     (proxyManager as unknown as { proxyProcess: IProxyProcess | null }).proxyProcess = fakeProcess;
     (proxyManager as unknown as { isInitialized: boolean }).isInitialized = true;