Reset Preferences does not reset preferences in other open MU instances

[krasko78]

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Open two or more instances of MU.
2. In any of them go to Edit -> Preferences.
3. Click on the Reset Preferences button in the lower left corner to reset all preferences to their defaults.
4. Confirm the reset on the dialog that appears.

Expected: all open instances should change to the reset preferences.
Actual: only the instance in which the reset is performed has its settings reset.

Additional info:

• PR25872 should be completed first (story [MU4 Issue] "Reset preferences" doesn't reset all preferences (e.g. advanced), no confirmation #11565)

• Currently the reset setting values cannot merely be sent to the other open instances, as this will only work partially due to some other minor bugs that need to be addressed here. In particular, if all setting values are sent to the other instances after the reset, the other instances will update but if you then click the Cancel button on the Preferences dialog, the current instance will remain with the reset settings whereas the other instances will revert to the values from before the reset. This is because the Settings::reset method cancels the transaction in the current instance without notifying the other instances so the reset happens without a transaction in the current instance (and is therefore not undoable even if the user then clicks the Cancel button) whereas it happens within a transaction in the other instances (and is therefore undoable when the user clicks the Cancel button).

• There exists a problem syncing the themes between all instances since the themes setting ui/application/themes is more than 2048 bytes long (on my machine it is 3531 bytes holding 4 themes) and the IPC communication cannot handle messages of more than 2048 bytes. See ipc::readFromSocket in ipc.cpp. This problem is reported in Crash when reseting the Appearance page of Preferences dialog to defaults #25323 and After customizing colors of multiple themes, theme changes stop being synced between instances (+assert fail in debug) #24724 and must be fixed before this one.

Supporting files, videos and screenshots

n/a

What is the latest version of MuseScore Studio where this issue is present?

4.4.4 and master

Regression

No.

Operating system

Windows 10 but practically any OS

Additional context

No response

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible