From bdc782617f1547b1e9631ba34ba8fba917ce767e Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 25 Sep 2020 11:27:30 -0700
Subject: [PATCH 1/2] return an error when we fail to find a sector when
 checking sector expiration

Returning nil, nil is a footgun.

fix: https://github.com/filecoin-project/lotus/issues/3984
---
 chain/actors/builtin/miner/v0.go | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/chain/actors/builtin/miner/v0.go b/chain/actors/builtin/miner/v0.go
index 9cdfc25bc..f5aa7849d 100644
--- a/chain/actors/builtin/miner/v0.go
+++ b/chain/actors/builtin/miner/v0.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/libp2p/go-libp2p-core/peer"
 	cbg "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-bitfield"
@@ -96,9 +97,7 @@ func (s *state0) NumLiveSectors() (uint64, error) {
 
 // GetSectorExpiration returns the effective expiration of the given sector.
 //
-// If the sector isn't found or has already been terminated, this method returns
-// nil and no error. If the sector does not expire early, the Early expiration
-// field is 0.
+// If the sector does not expire early, the Early expiration field is 0.
 func (s *state0) GetSectorExpiration(num abi.SectorNumber) (*SectorExpiration, error) {
 	dls, err := s.State.LoadDeadlines(s.store)
 	if err != nil {
@@ -161,7 +160,7 @@ func (s *state0) GetSectorExpiration(num abi.SectorNumber) (*SectorExpiration, e
 		return nil, err
 	}
 	if out.Early == 0 && out.OnTime == 0 {
-		return nil, nil
+		return nil, xerrors.Errorf("failed to find sector %d", num)
 	}
 	return &out, nil
 }

From ddcbcdea4809eb2e0c153207f9c8d1116d9cd1e8 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Fri, 25 Sep 2020 12:16:35 -0700
Subject: [PATCH 2/2] test sector status on expiring sectors

---
 api/test/ccupgrade.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/api/test/ccupgrade.go b/api/test/ccupgrade.go
index b281f30a0..f58f1ff6e 100644
--- a/api/test/ccupgrade.go
+++ b/api/test/ccupgrade.go
@@ -94,6 +94,22 @@ func TestCCUpgrade(t *testing.T, b APIBuilder, blocktime time.Duration) {
 		require.Less(t, 50000, int(exp.OnTime))
 	}
 
+	dlInfo, err := client.StateMinerProvingDeadline(ctx, maddr, types.EmptyTSK)
+	require.NoError(t, err)
+
+	// Sector should expire.
+	for {
+		// Wait for the sector to expire.
+		status, err := miner.SectorsStatus(ctx, CC, true)
+		require.NoError(t, err)
+		if status.OnTime == 0 && status.Early == 0 {
+			break
+		}
+		t.Log("waiting for sector to expire")
+		// wait one deadline per loop.
+		time.Sleep(time.Duration(dlInfo.WPoStChallengeWindow) * blocktime)
+	}
+
 	fmt.Println("shutting down mining")
 	atomic.AddInt64(&mine, -1)
 	<-done