issue with VDS and self referencing VirtualSource

[payno]

Describe the bug
It looks like there is some consistency or bug regarding 'self-referencing' VirtualSource (so if the source dataset is contained in the file containing also the virtual dataset - VDS)

Expected behavior
If a "file_name" contains a dataset referenced in VDS contained in the same file then if the virtual source path is "." or ".{file_name}" should have the same behavior

Platform (please complete the following information)
tested (only) with:

• HDF5version: 1.14.3
• OS and version: Ubuntu 20.04.6 LTS
• default HDF5 version provided by h5py wheel

Additional context
Here is some code to reproduce (using h5py):
first assertion works as expected, second one failed (using '.{file_path}' instead of '.')

import numpy
import h5py

print("** Write test datasets")
data = numpy.linspace(1, 10, 100, dtype=numpy.float32).reshape((10, 10))


with h5py.File("test.h5", mode="w") as h5f:
    h5f["/data"] = data
    vsource_1 = h5py.VirtualSource(".", "/data", shape=(10, 10))
    layout = h5py.VirtualLayout(shape=(10, 10), dtype="f4")
    layout[:] = vsource_1
    h5f.create_virtual_dataset("/vds_ok", layout, fillvalue=-5)

    vsource_1 = h5py.VirtualSource("./test.h5", "/data", shape=(10, 10))
    layout = h5py.VirtualLayout(shape=(10, 10), dtype="f4")
    layout[:] = vsource_1
    h5f.create_virtual_dataset("/vds_failed", layout, fillvalue=-5)


print("** Read with locking")
with h5py.File("test.h5", mode="r", locking=True) as h5f:
    vds_data = h5f["/vds_ok"][()]
    assert numpy.array_equal(data, vds_data)
    vds_data = h5f["/vds_failed"][()]
    assert numpy.array_equal(data, vds_data)


print("** Read without locking")
with h5py.File("test.h5", mode="r", locking=False) as h5f:
    print("  - VDS OK")
    vds_data = h5f["/vds_ok"][()]
    assert numpy.array_equal(data, vds_data)
    print("  - vds_failed")
    vds_data = h5f["/vds_failed"][()]
    assert numpy.array_equal(data, vds_data)

[fortnern]

Does this fail both with and without file locking?

[payno]

With file locking it works. Without it fails.