The README said check skips only "global heap collections other than
those a value read touches", but read_dataset returns the raw heap IDs,
so no collection was ever read: a file whose global heap collection
claims a 4 GiB object passed `check --data` with no problems, while
h5dump (and h5rs dump/diff) fail on it.
With --data, every variable-length element (strings and sequences, also
inside compounds, arrays and nested sequences) of every dataset and
attribute is followed into its collection. A collection that does not
parse, a missing heap object, or a sequence longer than its heap object
is a problem at the collection's address, once per object; the summary
counts the collections read.
Measured on tank, 2026-09-26: the 418 fully-read conformance ok files
still pass (scripts/h5rs-check-ok-files.sh --data, 0 flagged), and
`check --data` now flags 152 of the 180 CVE-corpus files (was 147); of
the 28 it passes, h5dump 1.14.6 rejects 21 (was 26 of 33).
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>