fix(core): exact-resume saved session on workspace reconnect (#315)

core/engine.go

@@ -1932,16 +1932,22 @@ func (e *Engine) getOrCreateInteractiveStateWith(sessionKey string, p Platform,
 		return state
 	}
 
-	// On first real-user connection after engine startup (or workspace re-creation
-	// after idle reap), use --continue to pick up the most recent CLI session.
-	// Subsequent connections respect the stored session ID (or "" for fresh).
+	// On first real-user connection after engine startup, use --continue to pick
+	// up the most recent CLI session. For workspace-scoped reconnects after idle
+	// reap, keep that behavior only when we do not already have a concrete saved
+	// agent session ID; otherwise exact resume is more precise than continuing
+	// whatever the CLI considers "latest" in that workspace.
 	startSessionID := session.GetAgentSessionID()
 	once := &e.hasConnectedOnce
 	if connectedOnce != nil {
 		once = connectedOnce
 	}
-	if consumeFirstUserContinueBridge && !once.Swap(true) {
-		startSessionID = ContinueSession
+	if consumeFirstUserContinueBridge {
+		if connectedOnce != nil && startSessionID != "" {
+			once.Store(true)
+		} else if !once.Swap(true) {
+			startSessionID = ContinueSession
+		}
 	}
 
 	isResume := startSessionID != ""

core/engine_test.go

@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 )
@@ -4450,6 +4451,47 @@ func TestFreshSessionRespectedAfterFirstConnection(t *testing.T) {
 	}
 }
 
+func TestWorkspaceReconnectWithSavedSessionIDSkipsContinueBridge(t *testing.T) {
+	agent := &stubStartSessionAgent{}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	e := &Engine{
+		agent:             agent,
+		sessions:          NewSessionManager(""),
+		ctx:               ctx,
+		i18n:              NewI18n("en"),
+		interactiveStates: make(map[string]*interactiveState),
+		display:           DisplayCfg{},
+	}
+
+	session := e.sessions.GetOrCreateActive("test:user3")
+	session.SetAgentSessionID("saved-session-id", "stub")
+
+	var wsConnectedOnce atomic.Bool
+	p := &stubPlatformEngine{n: "test"}
+	state := e.getOrCreateInteractiveStateWith("test:user3", p, "ctx", session, e.sessions, nil, "", true, &wsConnectedOnce)
+
+	if state.agentSession == nil {
+		t.Fatal("expected agentSession to be non-nil")
+	}
+	if !wsConnectedOnce.Load() {
+		t.Fatal("workspace connectedOnce flag should be marked after exact resume")
+	}
+
+	agent.mu.Lock()
+	calls := append([]string{}, agent.calls...)
+	agent.mu.Unlock()
+
+	if len(calls) != 1 {
+		t.Fatalf("expected 1 StartSession call, got %d: %v", len(calls), calls)
+	}
+	if calls[0] != "saved-session-id" {
+		t.Fatalf("StartSession call = %q, want saved session id", calls[0])
+	}
+}
+
 func TestParseSelfReportedCtx(t *testing.T) {
 	tests := []struct {
 		input string