fix session recovery for stale tool-call tails

pkg/session/jsonl_backend.go

@@ -38,7 +38,7 @@ func (b *JSONLBackend) GetHistory(key string) []providers.Message {
 		log.Printf("session: get history: %v", err)
 		return []providers.Message{}
 	}
-	return msgs
+	return sanitizeRecoveredHistory(msgs)
 }
 
 func (b *JSONLBackend) GetSummary(key string) string {

pkg/session/manager.go

@@ -97,7 +97,7 @@ func (sm *SessionManager) GetHistory(key string) []providers.Message {
 
 	history := make([]providers.Message, len(session.Messages))
 	copy(history, session.Messages)
-	return history
+	return sanitizeRecoveredHistory(history)
 }
 
 func (sm *SessionManager) GetSummary(key string) string {

pkg/session/recovery.go

@@ -0,0 +1,52 @@
+package session
+
+import "github.com/sipeed/picoclaw/pkg/providers"
+
+// sanitizeRecoveredHistory drops any dangling tail that starts with an
+// assistant tool-call message whose tool results were never fully persisted.
+//
+// This prevents a restarted agent from restoring an unfinished runtime state
+// (assistant tool calls plus later steering/user messages) as if it were valid
+// history. We keep completed tool-call sequences intact and only trim the
+// incomplete suffix.
+func sanitizeRecoveredHistory(history []providers.Message) []providers.Message {
+	for i := 0; i < len(history); i++ {
+		msg := history[i]
+		if msg.Role != "assistant" || len(msg.ToolCalls) == 0 {
+			continue
+		}
+
+		expected := make(map[string]bool, len(msg.ToolCalls))
+		for _, tc := range msg.ToolCalls {
+			expected[tc.ID] = false
+		}
+
+		j := i + 1
+		for ; j < len(history); j++ {
+			next := history[j]
+			if next.ToolCallID == "" {
+				break
+			}
+			if _, ok := expected[next.ToolCallID]; ok {
+				expected[next.ToolCallID] = true
+			}
+		}
+
+		complete := true
+		for _, found := range expected {
+			if !found {
+				complete = false
+				break
+			}
+		}
+		if !complete {
+			return append([]providers.Message(nil), history[:i]...)
+		}
+
+		if j > i+1 {
+			i = j - 1
+		}
+	}
+
+	return append([]providers.Message(nil), history...)
+}

pkg/session/recovery_test.go

@@ -0,0 +1,58 @@
+package session
+
+import (
+	"testing"
+
+	"github.com/sipeed/picoclaw/pkg/providers"
+)
+
+func TestSanitizeRecoveredHistory_DropsDanglingToolCallTail(t *testing.T) {
+	history := []providers.Message{
+		{Role: "user", Content: "hello"},
+		{Role: "assistant", Content: "working", ToolCalls: []providers.ToolCall{{ID: "call_1"}}},
+		{Role: "user", Content: "?"},
+	}
+
+	got := sanitizeRecoveredHistory(history)
+	if len(got) != 1 {
+		t.Fatalf("len(got) = %d, want 1", len(got))
+	}
+	if got[0].Content != "hello" {
+		t.Fatalf("got[0].Content = %q, want hello", got[0].Content)
+	}
+}
+
+func TestSanitizeRecoveredHistory_KeepsCompletedToolCallSequence(t *testing.T) {
+	history := []providers.Message{
+		{Role: "user", Content: "hello"},
+		{Role: "assistant", Content: "working", ToolCalls: []providers.ToolCall{{ID: "call_1"}, {ID: "call_2"}}},
+		{Role: "tool", ToolCallID: "call_1", Content: "done 1"},
+		{Role: "tool", ToolCallID: "call_2", Content: "done 2"},
+		{Role: "assistant", Content: "all set"},
+	}
+
+	got := sanitizeRecoveredHistory(history)
+	if len(got) != len(history) {
+		t.Fatalf("len(got) = %d, want %d", len(got), len(history))
+	}
+	if got[len(got)-1].Content != "all set" {
+		t.Fatalf("last content = %q, want all set", got[len(got)-1].Content)
+	}
+}
+
+func TestSanitizeRecoveredHistory_DropsPartialToolResultsAndFollowingMessages(t *testing.T) {
+	history := []providers.Message{
+		{Role: "user", Content: "hello"},
+		{Role: "assistant", Content: "working", ToolCalls: []providers.ToolCall{{ID: "call_1"}, {ID: "call_2"}}},
+		{Role: "tool", ToolCallID: "call_1", Content: "done 1"},
+		{Role: "user", Content: "still there?"},
+	}
+
+	got := sanitizeRecoveredHistory(history)
+	if len(got) != 1 {
+		t.Fatalf("len(got) = %d, want 1", len(got))
+	}
+	if got[0].Content != "hello" {
+		t.Fatalf("got[0].Content = %q, want hello", got[0].Content)
+	}
+}