routing: allow misson control manager to startup despite errors

We now allow the mission control manager to skip over deserializable
errors. We cannot repair this these results but we just skip over
it so we can startup properly.

Author: ziggie1984

routing/missioncontrol_store.go

@@ -141,8 +141,14 @@ func (b *missionControlStore) fetchAll() ([]*paymentResult, error) {
 
 		return resultBucket.ForEach(func(k, v []byte) error {
 			result, err := deserializeResult(k, v)
+
+			// In case of an error, we skip the result, otherwise we
+			// would not start up the node.
 			if err != nil {
-				return err
+				log.Warnf("Failed to deserialize result: %v",
+					err)
+
+				return nil
 			}
 
 			results = append(results, result)

routing/missioncontrol_store_test.go

@@ -332,3 +332,72 @@ func BenchmarkMissionControlStoreFlushing(b *testing.B) {
 		})
 	}
 }
+
+// TestMissionControlStoreSkipsCorruptedEntries tests that fetchAll() skips
+// entries that fail to deserialize rather than returning an error.
+func TestMissionControlStoreSkipsCorruptedEntries(t *testing.T) {
+	h := newMCStoreTestHarness(t, testMaxRecords, time.Second)
+	store := h.store
+
+	failureSourceIdx := 1
+
+	// Create two valid results.
+	result1 := newPaymentResult(
+		1, mcStoreTestRoute, testTime, testTime,
+		fn.Some(newPaymentFailure(
+			&failureSourceIdx,
+			lnwire.NewFailIncorrectDetails(100, 1000),
+		)),
+	)
+
+	result2 := newPaymentResult(
+		2, mcStoreTestRoute, testTime.Add(time.Hour),
+		testTime.Add(time.Hour),
+		fn.Some(newPaymentFailure(
+			&failureSourceIdx,
+			lnwire.NewFailIncorrectDetails(100, 1000),
+		)),
+	)
+
+	// Store both results.
+	store.AddResult(result1)
+	store.AddResult(result2)
+	require.NoError(t, store.storeResults())
+
+	// Verify both results are stored correctly.
+	results, err := store.fetchAll()
+	require.NoError(t, err)
+	require.Len(t, results, 2)
+
+	// Now manually insert a corrupted entry into the database.
+	// We'll create a key that looks valid but has corrupted value data.
+	err = store.db.update(func(bucket kvdb.RwBucket) error {
+		// Create a valid-looking key (8 bytes timestamp + 8 bytes id +
+		// 33 bytes pubkey).
+		var corruptedKey [8 + 8 + 33]byte
+		byteOrder.PutUint64(corruptedKey[:], uint64(testTime.Add(
+			30*time.Minute).UnixNano()),
+		)
+		byteOrder.PutUint64(corruptedKey[8:], 99) // Unique ID.
+		copy(corruptedKey[16:], result1.route.Val.sourcePubKey.Val[:])
+
+		// Insert corrupted/invalid TLV data that will fail to
+		// deserialize.
+		corruptedValue := []byte{0xFF, 0xFF, 0xFF, 0xFF}
+
+		return bucket.Put(corruptedKey[:], corruptedValue)
+	}, func() {})
+	require.NoError(t, err)
+
+	// Now fetch all results. The corrupted entry should be skipped,
+	// and we should get back only the two valid results.
+	results, err = store.fetchAll()
+	require.NoError(t, err, "fetchAll should not return an error "+
+		"even when encountering corrupted entries")
+	require.Len(t, results, 2, "should skip the corrupted entry and "+
+		"return only valid results")
+
+	// Verify we still have the correct results.
+	require.Equal(t, result1, results[0])
+	require.Equal(t, result2, results[1])
+}