zarray_get_ex() checked only idx >= caps, so a negative index read
array->data[idx] out of bounds -- reachable through a resource whose
registration failed and kept idx == -1 (xcelimit.c add_vres()). It now
returns NULL for idx < 0.
repl_info_resource_one() bounded a shared resource's slot by
sharedInst.count / sharedInUse.count, the number of populated slots, not
the capacity: a populated slot above that count showed as value=(none).
It now relies on zarray_get()'s own bounds check.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>