BizHawk is a multi-system emulator written in C#. BizHawk provides nice features for casual gamers such as full screen, and joypad support in addition to full rerecording and debugging tools for all system cores.
If a branch instruction wraps around, either from $FFzz to $00zz, or from $00zz to $FFzz, the tracelogger incorrectly shows the destination of the branch as more than a 16 bit value.
Repro
I created a custom cartridge for the purposes of reproducing this bug, (for the screenshot shared above)
The source code just writes 0xF0 and 0xEC at address $0009 and $000A to form a branch that underflows, then takes a branch from address $FFF5 that overflows.
Summary
If a branch instruction wraps around, either from $FFzz to $00zz, or from $00zz to $FFzz, the tracelogger incorrectly shows the destination of the branch as more than a 16 bit value.
Repro
I created a custom cartridge for the purposes of reproducing this bug, (for the screenshot shared above) The source code just writes 0xF0 and 0xEC at address $0009 and $000A to form a branch that underflows, then takes a branch from address $FFF5 that overflows.