Sorry, this was my fault; I'd tested my external mount helper changes, but not in the particular scenario that reproduces this bug (use of the bind/move/remount options). Ben Collins sent me a patch, which I've uploaded.
Sorry, this was my fault; I'd tested my external mount helper changes, but not in the particular scenario that reproduces this bug (use of the bind/move/remount options). Ben Collins sent me a patch, which I've uploaded.