Use after free when server is disconnected during netsplits.
Found by Joseph Bisch.
Use after free when SASL messages are received in unexpected order.
Found by Joseph Bisch.
Null pointer dereference when an “empty” nick has been observed by
Irssi. Found by Joseph Bisch.
When the number of windows exceed the available space, Irssi would
crash due to Null pointer dereference. Found by Joseph Bisch.
Certain nick names could result in out of bounds access when printing
theme strings. Found by Oss-Fuzz.