Intermitten crash with "m" keys on Windows

[edTheGuy00]

I have been having irregular crashes on Windows release builds. Something like 1 out of 5 release build will randomly have this issue while the other 4 work perfectly fine even though nothing has changed at all. I was finally able to catch the bug in the logs:

flutter: The following assertion was thrown during a platform message callback:
flutter: Attempted to send a key down event when no keys are in keysPressed. This state can occur if the key
flutter: event being sent doesn't properly set its modifier flags. This was the event:
flutter: RawKeyDownEvent#18da2(logicalKey: LogicalKeyboardKey#0006d(keyId: "0x0000006d", keyLabel: "m",
flutter: debugName: "Key M"), physicalKey: PhysicalKeyboardKey#700e1(usbHidUsage: "0x000700e1", debugName:
flutter: "Shift Left")) and its data: RawKeyEventDataLinux(keyLabel: m, keyCode: 77, scanCode: 50,
flutter: unicodeScalarValues: 109, modifiers: 0, modifiers down: {})
flutter: 'package:flutter/src/services/raw_keyboard.dart':
flutter: Failed assertion: line 617 pos 12: '<optimized out>'

I noticed that it usually happens when typing something like @gmail which requires shift press. Potentially related? #502
So far we found this issue on a Surface laptop and Macbook running Windows via Bootcamp. This issue doesn't happen at all on MacOS.

[pchampio]

This isn't related to #502. #502 is about a GLFW exception that occurs when GLFW isn't able to query the scanecode from a given key. (even through the error was forwarded back to Flutter.)

This issue (a assertion) only occurs in the Flutter framework.
Source of the thrown issue:
https://github.com/flutter/flutter/blob/148ae7bf714a907c62b394359d44db246084e9a7/packages/flutter/lib/src/services/raw_keyboard.dart#L627-L630

It should not affect text input, only keyevent. In your example, I hope you were able to enter an email address in a InputText. (Even through the assertion was raised)

What's is happening is that flutter differentiate the LogicalKeyboardKey and the PhysicalKeyboardKey.
From the flutter documentations: https://api.flutter.dev/flutter/services/PhysicalKeyboardKey-class.html

(PhysicalKeyboardKey) represent physical keys, which are keys which represent a particular key location on a QWERTY keyboard. It ignores any modifiers, modes, or keyboard layouts which may be in effect. This is contrast to LogicalKeyboardKey, which represents a logical key interpreted in the context of modifiers, modes, and/or keyboard layouts.

As an example, if you wanted a game where the key next to the CAPS LOCK (the "A" key on a QWERTY keyboard) moved the player to the left, you'd want to look at the physical key to make sure that regardless of the character the key produces, you got the key that is in that location on the keyboard.

Conversely, if you wanted to implement an app where the "Q" key "quit" something, you'd want to look at the logical key to detect this, since you would like to have it match the key with "Q" on it, instead of always looking for "the key next next to the TAB key", since on a French keyboard, the key next to the TAB key has an "A" on it.

An easy way to trigger this assertion on linux is to remap the Caps Lock key to escape (Haven't you already done it! Men, it's the best!) setxkbmap -option caps:escape
and press Caps Lock on a flutter.

flutter: Attempted to send a key down event when no keys are in keysPressed. This state can occur if the key
flutter: event being sent doesn't properly set its modifier flags. This was the event:
flutter: RawKeyDownEvent#882ca(logicalKey: LogicalKeyboardKey#70029(keyId: "0x100070029", keyLabel: "",
flutter: debugName: "Escape"), physicalKey: PhysicalKeyboardKey#70039(usbHidUsage: "0x00070039", debugName:
flutter: "Caps Lock")) and its data: RawKeyEventDataLinux(keyLabel: , keyCode: 256, scanCode: 66,
flutter: unicodeScalarValues: 0, modifiers: 0, modifiers down: {})

Flutter doesn't know what do to with this LogicalKeyboardKey Escape key bind-ed to a PhysicalKeyboardKey Caps Lock.
And in your situation, it might be the same,

So far we found this issue on a Surface laptop and Macbook running Windows via Bootcamp

might simply have non conventional LogicalKeyboardKey / PhysicalKeyboardKey mapping.

I don't have time to work on this (and honesty it might not be a go-flutter issue but a flutter/flutter one), but if you want to work on a fix.
(https://github.com/go-flutter-desktop/go-flutter/wiki/Setting-up-hover-to-use-a-home-made-version-of-'go-flutter'#work-on-go-flutter-source-code)
please checkout the flutter flutter/keyevent system channel.

go-flutter/key-events.go

Line 42 in 67ff5ca

event, err := keyboard.Normalize(key, scancode, mods, action)

AND
the internal golang keyboard nomalizer we are using https://github.com/go-flutter-desktop/go-flutter/tree/master/internal/keyboard