fix(format): read array members of version-1 compound datatypes

HDF5 1.6 encoded a compound member that is a fixed-size array through legacy per-member fields (dimensionality, permutation, four dimension sizes) that the v1 decoder skipped, so a [4] i32 member read as one i32 with the wrong size. Build the array type from those fields as libhdf5 does (ignoring the permutation) and refuse more than four dimensions. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
2026-09-25 22:07:50 -05:00
parent 42b81d9f1c
commit efc2dc53c9
3 changed files with 98 additions and 1 deletions
@@ -273,6 +273,12 @@
 - CI keeps zlib-ng building and tested; the arm64 job no longer needs cmake.

 ### Correctness
+- `clawhdf5-format` reader: array members of version-1 compound datatypes
+  (HDF5 1.6-era files, e.g. libhdf5's `tcompound.h5`) were read as a single
+  element: a `[4] i32` member came back as one `i32`, with the wrong size.
+  The legacy per-member dimension fields are now decoded into an array type,
+  as libhdf5 does; more than four dimensions, or a zero-sized one, is an
+  error.
 - `clawhdf5-format` reader — **values returned wrong with no error:**
  - Fixed Array and Extensible Array chunk indexes were laid out by the
    dataset's current shape instead of its max shape (23 libhdf5 test files,