Crash without any error dialog

[binarycow]

Steps to replicate:

• Open Mesen 0.9.9, Build date 2020-02-01, on Windows 10 version 1909 (Build 18363.657)

• Load nestest-automated.nes

• Open the debugger

• Open the trace logger

• In the debugger, power cycle the NES

• Click "Clear Log" in the trace logger

• In the trace logger, click "Start Logging" and select a file

• In the debugger, click the "Continue" button

• MESEN crashes

nestest-automated.nes is the normal nestest.nes file, with 0xC000 manually entered in the reset vector: nestest-automated.nes.zip

Here are my Mesen settings: settings.zip

And here's the debugger files. Note that in the trace log, it seemed to crash in the middle of an RTS instruction. nestest-automated.Workspace.zip

Additionally, note that when running this rom in Mesen (without the debugger attached) it states "Game has crashed (Invalid OP code - CPU crashed.)"

• the rom works perfectly fine without my manual reset vector change (but is interactive, not automated)
• Even if an invalid opcode causes the emulated CPU to crash, this should not crash the application.

[SourMesen]

Thanks for the report.

I haven't investigated in depth yet, but it looks like the crash may be due to the ROM attempting to execute code from unmapped memory (e.g open bus) at $5xxx, which is causing issues with some of the debugger logic (and crashes in the debugger's code.)

It does not appear to be related to invalid opcodes - these are treated as any other op code, the only difference is that a message is shown when a "halt" opcode is hit to inform the user the game has crashed.

[SourMesen]

The crashes should be fixed as of the latest commit - thanks again for the report!