The previous comparator returned false when either rideLhs or rideRhs was a nullptr, in an attempt to avoid null pointer dereference. However, this causes both comp(a, nullptr) and comp(nullptr, a) to return false, which violates the requirements of a strict weak ordering.
As defined in the C++ standard, the comparator used in std::sort must establish a strict weak ordering. This includes the requirement that the equivalence relation defined as
equiv(a, b) := !comp(a, b) && !comp(b, a) must be transitive.
In the original logic, two non-null elements a and b might be ordered such that comp(a, b) == true but if both comp(a, nullptr) and comp(b, nullptr) return false, then equiv(a, nullptr) == true and equiv(b, nullptr) == true, which implies equiv(a, b) == true. This contradicts comp(a, b) == true and violates transitivity of equiv.
Such violations can lead to undefined behavior in std::sort, including invalid memory access or segmentation faults.
Fix the comparator to consistently treat nullptr as greater than any non-null pointer, by returning rideLhs != nullptr when either pointer is null. This restores transitivity and compliance with the C++ standard, ensuring reliable and predictable sorting behavior.
* Add RCT1 land edge door map animations
* Only animate landscape edge doors if door exists
* Move Vehicle::UpdateLandscapeDoorA function
* Merge Vehicle::UpdateLandscapeDoor functions
* Only animate land edge doors if track is below surface height
* Play door sounds for land edge doors
* Add changelog entry for landscape edge door animations
Some viewports, like the one in the guest window or the ride window, are
solely for the purpose of following a sprite. User could still try
RMB-dragging in those windows, which would result in the viewport no
longer following the sprite, but also not scrolling and simply getting
stuck at whatever the latest position was. This change prevents allowing
those viewports from unfollowing a sprite.
As shown in https://github.com/OpenRCT2/OpenRCT2/pull/24618, the steam
overlay feature doesn't work well and can cause jarring user experience
in some scenarios. It is only supported in the software renderer and
with code moving steadily to OpenGL, the time has come to remove a
broken feature.
