RFR: 8273506: java Robot API did the 'm' keypress and caused /awt/event/KeyEvent/KeyCharTest/KeyCharTest.html is timing out on macOS 12

[Dmitry Batrak]

On Wed, 20 Apr 2022 17:04:09 GMT, Alexander Zuev <kizune at openjdk.org> wrote:

> Clear the kCGEventFlagMaskSecondaryFn flag if it is set before posting keyboard events to the system queue.

Just a note - with the proposed fix, some generated events will be different from those generated by a real keyboard - namely events for arrow keys and F1-F12 keys, as those have 'inherent' Fn modifier set, regardless of whether Fn key was pressed during event generation. This won't be observable from Java applications, as Java APIs don't expose Fn modifier in `KeyEvent`-s, but can theoretically make some difference when interacting with other apps (I don't know about any problematic cases currently though). If this can be considered a problem, it's possible to improve the fix by not clearing Fn flag for key events 'inherently' having that Fn modifier. Simple approach might just hard-code them, and a more robust one (but a bit more complicated as well) can determine the set of affected keycodes on Robot startup, by examining flags set by `CGEventCreateKeyboardEvent` in a 'clear' event source state.

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PR: https://git.openjdk.java.net/jdk/pull/8320