The reader looks for the goniometer by walking every leaf of /entry/sample/transformations and
calling ReadAxis on each, stopping early only at an axis that is scanning. Not every leaf is an
axis: the writer's own AXISNAME_end and the two rotation-width scalars carry units and nothing else,
and ReadAxis threw when transformation_type was absent.
A sweep survived on alphabetical order alone - omega sorts before omega_end, so the walk stopped
before reaching it. A stationary axis never stopped, reached omega_end, and the open failed
outright with "Cannot open attribute transformation_type". This branch is what made that reachable,
by giving a still and a grid scan a spindle that stands still: rugnux read a grid-scan master, got a
stationary axis, wrote _process.h5 through the goniometer path - which does emit omega_end - and
could no longer open its own output.
ReadAxis now treats a missing transformation_type as "not a transformation" and skips it, which is
also what makes the search safe against anything a third party leaves in that group.
JFJochReader_AxisRecovery covers what the reader has to recover: a sweep, a sweep about an axis that
is not called omega, a spindle that does not turn, a grid scan alone and under a turning spindle,
and a sweep with the head at a Smargon position.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VfYvJT5Nb71suJCowRBn5z
leonarski_fandClaude Opus 5
d0ac559e64