Ticket #16152: sym-bug.cxc

# Fetch map and models
open emdb:18049
open 8q04
open alphafold:A0A8A2F5Y7
open alphafold:Q33BU5

# Align AF models to PDB model, discard PDB model
mmaker #3 to #2/a
mmaker #4 to #2/c
close #2

# The two AF models become chain A and B in a combined model of the asymmetric unit
combine #3,4
close #3,4

# Make sure this new asymmetric unit model fits the map
fit #2 in #1

# Apply D4 symmetry to the asymmetric unit
hide #2 models
view orient
sym #2 D4 center cofr addMmcifAssembly true

# Discard combination
close #3

# Save asymmetric unit as CIF
save /tmp/d4-ASU-model.cif model #2

# Re-open that file; it now has an assembly annotation, as expected
open /tmp/d4-ASU-model.cif

# Regenerate the assembly stored in the file
sym #3 assembly 1

# My expectation: the whole ASU (two chains) gets copied with the D4 symmetry
# The actual result: there is no chain B in the generated assembly
sel #4/a
# 3800 residues selected
sel #4/b
# Nothing selected; why did chain B not get included in the asymmetric unit?