From 7b9ae91e04f7d715a016df397f69c6d4444131f8 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Sun, 7 Nov 2021 22:33:44 +0100
Subject: [PATCH] copy: Load snapshots before indexes

---
 cmd/restic/cmd_check.go                  |  4 ++++
 internal/checker/checker.go              | 14 +++++++++++---
 internal/checker/checker_test.go         |  4 ++++
 internal/checker/testing.go              |  5 +++++
 internal/repository/master_index_test.go |  5 +++++
 5 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/cmd/restic/cmd_check.go b/cmd/restic/cmd_check.go
index fa71bdba8..e7edff39e 100644
--- a/cmd/restic/cmd_check.go
+++ b/cmd/restic/cmd_check.go
@@ -211,6 +211,10 @@ func runCheck(opts CheckOptions, gopts GlobalOptions, args []string) error {
 	}
 
 	chkr := checker.New(repo, opts.CheckUnused)
+	err = chkr.LoadSnapshots(gopts.ctx)
+	if err != nil {
+		return err
+	}
 
 	Verbosef("load indexes\n")
 	hints, errs := chkr.LoadIndex(gopts.ctx)
diff --git a/internal/checker/checker.go b/internal/checker/checker.go
index 93e58cedc..8e49209f5 100644
--- a/internal/checker/checker.go
+++ b/internal/checker/checker.go
@@ -11,6 +11,7 @@ import (
 	"sync"
 
 	"github.com/minio/sha256-simd"
+	"github.com/restic/restic/internal/backend"
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/hashing"
@@ -35,6 +36,7 @@ type Checker struct {
 	trackUnused bool
 
 	masterIndex *repository.MasterIndex
+	snapshots   restic.Lister
 
 	repo restic.Repository
 }
@@ -75,6 +77,12 @@ func (err ErrOldIndexFormat) Error() string {
 	return fmt.Sprintf("index %v has old format", err.ID.Str())
 }
 
+func (c *Checker) LoadSnapshots(ctx context.Context) error {
+	var err error
+	c.snapshots, err = backend.MemorizeList(ctx, c.repo.Backend(), restic.SnapshotFile)
+	return err
+}
+
 // LoadIndex loads all index files.
 func (c *Checker) LoadIndex(ctx context.Context) (hints []error, errs []error) {
 	debug.Log("Start")
@@ -278,8 +286,8 @@ func (c *Checker) checkTreeWorker(ctx context.Context, trees <-chan restic.TreeI
 	}
 }
 
-func loadSnapshotTreeIDs(ctx context.Context, repo restic.Repository) (ids restic.IDs, errs []error) {
-	err := restic.ForAllSnapshots(ctx, repo.Backend(), repo, nil, func(id restic.ID, sn *restic.Snapshot, err error) error {
+func loadSnapshotTreeIDs(ctx context.Context, lister restic.Lister, repo restic.Repository) (ids restic.IDs, errs []error) {
+	err := restic.ForAllSnapshots(ctx, lister, repo, nil, func(id restic.ID, sn *restic.Snapshot, err error) error {
 		if err != nil {
 			errs = append(errs, err)
 			return nil
@@ -300,7 +308,7 @@ func loadSnapshotTreeIDs(ctx context.Context, repo restic.Repository) (ids resti
 // subtrees are available in the index. errChan is closed after all trees have
 // been traversed.
 func (c *Checker) Structure(ctx context.Context, p *progress.Counter, errChan chan<- error) {
-	trees, errs := loadSnapshotTreeIDs(ctx, c.repo)
+	trees, errs := loadSnapshotTreeIDs(ctx, c.snapshots, c.repo)
 	p.SetMax(uint64(len(trees)))
 	debug.Log("need to check %d trees from snapshots, %d errs returned", len(trees), len(errs))
 
diff --git a/internal/checker/checker_test.go b/internal/checker/checker_test.go
index 948d5a480..1330211eb 100644
--- a/internal/checker/checker_test.go
+++ b/internal/checker/checker_test.go
@@ -44,6 +44,10 @@ func checkPacks(chkr *checker.Checker) []error {
 }
 
 func checkStruct(chkr *checker.Checker) []error {
+	err := chkr.LoadSnapshots(context.TODO())
+	if err != nil {
+		return []error{err}
+	}
 	return collectErrors(context.TODO(), func(ctx context.Context, errChan chan<- error) {
 		chkr.Structure(ctx, nil, errChan)
 	})
diff --git a/internal/checker/testing.go b/internal/checker/testing.go
index d672911b1..0668406d8 100644
--- a/internal/checker/testing.go
+++ b/internal/checker/testing.go
@@ -20,6 +20,11 @@ func TestCheckRepo(t testing.TB, repo restic.Repository) {
 		t.Fatalf("errors loading index: %v", hints)
 	}
 
+	err := chkr.LoadSnapshots(context.TODO())
+	if err != nil {
+		t.Error(err)
+	}
+
 	// packs
 	errChan := make(chan error)
 	go chkr.Packs(context.TODO(), errChan)
diff --git a/internal/repository/master_index_test.go b/internal/repository/master_index_test.go
index f1fe9af7e..2470dadfc 100644
--- a/internal/repository/master_index_test.go
+++ b/internal/repository/master_index_test.go
@@ -369,6 +369,11 @@ func TestIndexSave(t *testing.T) {
 	}
 
 	checker := checker.New(repo, false)
+	err = checker.LoadSnapshots(context.TODO())
+	if err != nil {
+		t.Error(err)
+	}
+
 	hints, errs := checker.LoadIndex(context.TODO())
 	for _, h := range hints {
 		t.Logf("hint: %v\n", h)