Bug#988086: Exim delivery process crashes on each mail with NULL-pointer

[halfdog]

Also 4.94.2-1 crashes, e.g. calling "exim4 -qff":

(gdb) bt
#0  0x000055ebf469d87c in log_open_already_exim (name=0x7ffcc589d560 "")
    at log.c:288
#1  0x000055ebf469dadf in log_open_as_exim (name=name at entry=0x7ffcc589d560 "")
    at log.c:416
#2  0x000055ebf469de8d in open_log (fd=fd at entry=0x55ebf476aed0 <mainlogfd>, 
    type=type at entry=0, tag=tag at entry=0x0) at log.c:552
#3  0x000055ebf469e86b in open_logs () at log.c:1512
#4  0x000055ebf46f61e8 in appendfile_transport_setup (tblock=0x55ebf675a688, 
    addrlist=<optimized out>, dummy=<optimized out>, uid=<optimized out>, 
    gid=<optimized out>, errmsg=0x55ebf6764908) at appendfile.c:238
#5  0x000055ebf466cc6d in deliver_local (addr=addr at entry=0x55ebf6764838, 
    shadowing=shadowing at entry=0) at deliver.c:2322
#6  0x000055ebf4677bc9 in do_local_deliveries () at deliver.c:3015
#7  deliver_message (id=id at entry=0x55ebf675ad21 "1ldz84-0001x1-8V", 
    forced=forced at entry=1, give_up=give_up at entry=0) at deliver.c:7209
#8  0x000055ebf46a7f9f in queue_run (start_id=start_id at entry=0x0, 
    stop_id=stop_id at entry=0x0, recurse=recurse at entry=0) at queue.c:662
#9  0x000055ebf465aac9 in main (argc=2, cargv=<optimized out>) at exim.c:4715