A grid scan with no goniometer and no Smargon head has the placeholder omega as
the only rotation axis in its sample chain - grid_scan_x and grid_scan_y are
translations, and a reader looking for a scan axis passes over them. Written as
a scalar, the whole scan therefore read back as a single image.
This is the defect the Smargon change fixed for a still at a head position, and
its reasoning applies here verbatim: a reader takes the image count from the
innermost axis of the chain when no axis varies. Write the placeholder the same
way, one entry per image.
The reader round-trip could not see it - our own reader handles a rank-0 dataset
- so the test asserts the stored shape instead. Reverted against the fix it
fails with rank 0, dim 0 against the expected 5.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y5XisyYxmF8mUEQjzpMRe2
leonarski_fandClaude Opus 5
00535a7486