r->useragent_addr is assigned on ap_read_request (http_core.c),
called from ap_process_http_(async_)connection
called from process_connection hook (APR_HOOK_REALLY_LAST).
The SEGV occured on process_connection hook, maybe before
ap_process_http_(async_)connection,
#11 0x00007fd44f91fd4f in modperl_callback_connection (idx=<optimized
out>, c=<optimized out>,
run_mode=<optimized out>) at modperl_callback.c:359
#12 0x000055feaf10cdf0 in ap_run_process_connection
(c=c@entry=0x7fd4461f22b8) at connection.c:42
#13 0x000055feaf10d340 in ap_process_connection
(c=c@entry=0x7fd4461f22b8, csd=csd@entry=0x7fd4461f20a0)
at connection.c:226
so r->useragent_addr had not been assigned any value.
