GH-430: Fixed 'Close' confirmation is ignored. (This worked on macOS, but I could reproduce it on Windows. It should be fixed now.)

Tested and working on Windows 👍

Thanks for the great work Akos. Super awesome how you were able to make these fixes and improvements

Regarding this:

GH-432: Made compile/verify work on dirty editors. (Compile/Upload/Upload using programmer should work on dirty editors.)

I spotted an issue. It might be something to deal with separately, if so I can open an issue, but I thought I should mention it here:

Describe the bug
The dirty code is compiled (good), but the code from the saved version of the sketch is used in the error message when there is a compilation failure (bad).

To Reproduce
Steps to reproduce the behavior:

1. File > Preferences
2. Uncheck the box next to "Auto save".
3. Click the "OK" button.
4. Open a sketch that will compile without errors (e.g., File > New).
5. Make changes to the sketch code that would cause a compilation failure. Don't save.
6. Sketch > Verify/Compile. The compilation fails.
7. Check the error message in the output menu. The quoted line of code is from the saved version of the sketch, not the code that caused the error.

For example, if I have this sketch saved:

void setup() {}
void loop() {}

and this is the dirty version:

foovoid setup() {}
void loop() {}

The compilation error:

c:\Users\per\AppData\Local\Temp\.arduinoIDE-unsaved2021112-12840-1u0f2iv.mccj\sketch_feb12a\sketch_feb12a.ino:1:1: error: 'foovoid' does not name a type; did you mean 'void'?
 void setup() {}
 ^~~~~~~
 void
c:\Users\per\AppData\Local\Temp\.arduinoIDE-unsaved2021112-12840-1u0f2iv.mccj\sketch_feb12a\sketch_feb12a.ino:1:1: error: 'foovoid' does not name a type; did you mean 'void'?
 void setup() {}
 ^~~~~~~
 void
Compilation error: Error: 2 UNKNOWN: exit status 1

The compilation error if I save the sketch:

c:\Users\per\AppData\Local\Temp\.arduinoIDE-unsaved2021112-12840-1u0f2iv.mccj\sketch_feb12a\sketch_feb12a.ino:1:1: error: 'foovoid' does not name a type; did you mean 'void'?
 foovoid setup() {}
 ^~~~~~~
 void
c:\Users\per\AppData\Local\Temp\.arduinoIDE-unsaved2021112-12840-1u0f2iv.mccj\sketch_feb12a\sketch_feb12a.ino:1:1: error: 'foovoid' does not name a type; did you mean 'void'?
 foovoid setup() {}
 ^~~~~~~
 void
Compilation error: Error: 2 UNKNOWN: exit status 1

I'm not sure what is going on with the doubled output and that stray void.

Describe the bug
The dirty code is compiled (good), but the code from the saved version of the sketch is used in the error message when there is a compilation failure (bad).

I can confirm the bug. I think it might be a CLI issue. I am not doing anything special, but using the appropriate CLI API.

I'm not sure what is going on with the doubled output and that stray void.

I see this issue (but not #12) also occurs in Java IDE 1.8.13. The duplicate error messages are caused by the error propagating to the hidden function prototype generated during sketch preprocessing:

#include <Arduino.h>
#line 1 "C:\\Users\\per\\Documents\\Arduino\\Issue12\\Issue12.ino"
#line 1 "C:\\Users\\per\\Documents\\Arduino\\Issue12\\Issue12.ino"
foovoid setup();
#line 2 "C:\\Users\\per\\Documents\\Arduino\\Issue12\\Issue12.ino"
void loop();
#line 1 "C:\\Users\\per\\Documents\\Arduino\\Issue12\\Issue12.ino"
foovoid setup() {}
void loop() {}

And the void is just the suggested fix. So this is nothing specific to Arduino IDE 2.0.0 and only occurs under specific circumstances.