With a 2.0 low version bound, libhdf5 stores the VDS mapping list as heap
block version 1: every entry starts with a flags byte (0x04 same file, no
file name; 0x01/0x02 file/dataset name shared with an earlier entry, whose
index is stored in place of the name). The parser treated only a leading
0x04 byte as special, so a 0x00 flags byte read as an empty (same-file)
name and shared names were read as garbage.
Decode it as H5D__virtual_load_layout does, refusing unknown flags,
forward references and block versions above 1.
Test: vds_interop::vds_mapping_block_version1_shared_names (h5py
libver=("v200","v200") with repeated long names; failed before with
"unknown dataspace selection type") plus the exact heap block as a unit
test.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
