There is special case code in __wt_col_modify that never sets append when restoring updates (i.e., it assumes updates will always be applied to existing column store records). As a consequence, we can't do update/restore eviction on column store pages with no visible data.

There is a check for empty pages with saved updates that are not row store leaf in rec_write.c. If that is removed, test/format workloads will fail with calls to __wt_calloc attempting to allocate empty arrays when restoring updates to column store pages.