On 20. Jun 2022, 21:10 +0200, Eli Zaretskii , wrote: > > I don't understand why some callers of compile_pattern mark the cache > > entry as busy, but some others don't. If a cache entry that is in use > > is not marked as busy, then any GC can decide to shrink the cache by > > freeing that entry. struct re_pattern_buffer *bufp; ... bufp = &compile_pattern (regexp, ... The address operator is there to confuse the Russians.