Connecting reset an existing physical monitor's refresh (e.g. 120->60 Hz)
because the topology code read the physical's mode AFTER the virtual output
perturbed the compositor layout — by which point it had already been
downgraded. Read/preserve each physical's mode from a pre-connect snapshot.
- Mutter: build_primary_keeping_physicals takes the pre-virtual snapshot and
preserves each physical's real mode (pick_keep_mode, unit-tested)
- KWin: capture each output's mode when disabling for exclusive, re-assert it
on re-enable (a bare enable defaulted to ~60 Hz)
- Windows: skip the refresh-resetting SDC_TOPOLOGY_EXTEND when a physical is
already active
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
a947f48d29