From 1f4c9d280629f2afde9c6a294590f73962b37e83 Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Thu, 29 Aug 2024 16:32:15 +0200
Subject: [PATCH] cache: correctly ignore files whose filename is no ID

this can for example be the case for temporary files created by the
backend implementation.
---
 internal/backend/cache/backend.go      |  5 ++---
 internal/backend/cache/backend_test.go | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/internal/backend/cache/backend.go b/internal/backend/cache/backend.go
index 58b03dd38..3754266ba 100644
--- a/internal/backend/cache/backend.go
+++ b/internal/backend/cache/backend.go
@@ -231,9 +231,8 @@ func (b *Backend) List(ctx context.Context, t backend.FileType, fn func(f backen
 	wrapFn := func(f backend.FileInfo) error {
 		id, err := restic.ParseID(f.Name)
 		if err != nil {
-			// returning error here since, if we cannot parse the ID, the file
-			// is invalid and the list must exit.
-			return err
+			// ignore files with invalid name
+			return nil
 		}
 
 		ids.Insert(id)
diff --git a/internal/backend/cache/backend_test.go b/internal/backend/cache/backend_test.go
index dca51c2bf..7f83e40cb 100644
--- a/internal/backend/cache/backend_test.go
+++ b/internal/backend/cache/backend_test.go
@@ -296,3 +296,20 @@ func TestAutomaticCacheClear(t *testing.T) {
 		t.Errorf("cache doesn't have file2 after list")
 	}
 }
+
+func TestAutomaticCacheClearInvalidFilename(t *testing.T) {
+	be := mem.New()
+	c := TestNewCache(t)
+
+	data := test.Random(rand.Int(), 42)
+	h := backend.Handle{
+		Type: backend.IndexFile,
+		Name: "tmp12345",
+	}
+	save(t, be, h, data)
+
+	wbe := c.Wrap(be)
+
+	// list all files in the backend
+	list(t, wbe, func(_ backend.FileInfo) error { return nil })
+}