Add test for listing filesets without local database.

This test would have failed prior to the changes in revision 8ab64071f0
("Display correct backup type when using direct restore").  Prior to
revision 8ab64071f0, all filesets would have been marked as partial when
performing a direct restore without the local database.

This concerns issue #3982.

Duplicati/UnitTest/DisruptionTests.cs

@@ -193,6 +193,35 @@ namespace Duplicati.UnitTest
             }
         }
 
+        [Test]
+        [Category("Disruption")]
+        public async Task ListWithoutLocalDb()
+        {
+            // Choose a dblock size that is small enough so that more than one volume is needed.
+            Dictionary<string, string> options = new Dictionary<string, string>(this.TestOptions)
+            {
+                ["dblock-size"] = "10mb",
+                ["no-local-db"] = "true"
+            };
+
+            // Run a full backup.
+            using (Controller c = new Controller("file://" + this.TARGETFOLDER, options, null))
+            {
+                c.Backup(new[] {this.DATAFOLDER});
+            }
+
+            // Run a partial backup.
+            using (Controller c = new Controller("file://" + this.TARGETFOLDER, options, null))
+            {
+                await this.RunPartialBackup(c).ConfigureAwait(false);
+
+                List<IListResultFileset> filesets = c.List().Filesets.ToList();
+                Assert.AreEqual(2, filesets.Count);
+                Assert.AreEqual(BackupType.FULL_BACKUP, filesets[1].IsFullBackup);
+                Assert.AreEqual(BackupType.PARTIAL_BACKUP, filesets[0].IsFullBackup);
+            }
+        }
+
         [Test]
         [Category("Disruption")]
         public async Task RetentionPolicyRetention()