mountmgr: Assign a unique nonzero serial to all volumes.

dlls/mountmgr.sys/device.c

@@ -1123,6 +1123,9 @@ static NTSTATUS set_volume_info( struct volume *volume, struct dos_drive *drive,
         }
     }
 
+    if (!volume->serial)
+        memcpy(&volume->serial, &volume->guid.Data4[4], sizeof(DWORD));
+
     if (!volume->mount)
         volume->mount = add_volume_mount_point( disk_device->dev_obj, &disk_device->name, &volume->guid );
     if (drive && !drive->mount)

dlls/ntdll/tests/file.c

@@ -3908,7 +3908,7 @@ static void test_query_volume_information_file(void)
      io.Information);
 
     todo_wine ok(ffvi->VolumeCreationTime.QuadPart != 0, "Missing VolumeCreationTime\n");
-    todo_wine ok(ffvi->VolumeSerialNumber != 0, "Missing VolumeSerialNumber\n");
+    ok(ffvi->VolumeSerialNumber != 0, "Missing VolumeSerialNumber\n");
     ok(ffvi->SupportsObjects == 1,"expected 1, got %d\n", ffvi->SupportsObjects);
     ok(ffvi->VolumeLabelLength == lstrlenW(ffvi->VolumeLabel) * sizeof(WCHAR), "got %d\n", ffvi->VolumeLabelLength);