A hybrid master carries an NXmx /entry/sample/transformations group holding one EMPTY SUBGROUP per
axis - the direction as a vector attribute, no NX_class, no units, no angles - beside a legacy
/entry/sample/goniometer group holding all the angles. Opening it failed outright with "Cannot open
HDF5 dataset /entry/sample/transformations/omega": the existing legacy fallback keys off
Exists("/entry/sample/transformations"), which is true here, so it never fired, and the axis stub
was then opened as if it were the angle dataset.
Present is not the same as usable. GoniometerGroup now takes transformations only if it holds at
least one DATASET, and ReadAxis asks IsDataSet rather than Exists, so a member that is not a dataset
can no longer be read as one. HDF5Object gains that predicate, in the style of the neighbouring
Exists.
The stub is the load-bearing half, not merely the thing that crashed. In the legacy branch, before
falling back to the assumed (-1,0,0), the reader now looks for the NXmx stub and takes its stated
vector. With it the axis is (0,-1,0) and the run indexes 60/60 validation frames; with the stub
deleted the assumption applies and the same file indexes 0/60 on both schemes and both signs, and
the run stops with no lattice. So without this half the fix would have turned "cannot open" into
"found no lattice" - a differently shaped failure, not a success. The direction stated here is 90
degrees from the assumption, not merely its negation, which the rotation first pass could have
recovered on its own.
The vector size check moved out of the first branch so it now covers every path that produces one.
Verified: the file processes end to end, 100% of frames indexed, cubic cell 105.87 against a
deposited 105.88 (0.009%), space group reported as I23 or I213 - correctly refusing to choose, since
the reflections that separate them are extinguished by the I-centring and were never measured. A
both-layout master reprocesses unchanged (100% indexed, P212121). [HDF5] passes: 2194 assertions in
91 cases.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lc5JG6kJqZoCWaoZ43JGTW
leonarski_fandClaude Opus 5
1ea6ba25be