Fix: Use of unstable sort when distributing cargo production can caus… #9460
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glx22
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backport requested
JGRennison
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Jul 31, 2021
…e desyncs (cherry picked from commit 4ed694fe98b146d984826d06b96e0c11045239bc) See: OpenTTD/OpenTTD#9460
rubidium42
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Aug 1, 2021
TrueBrain
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Motivation / Problem
Unstable
std::sortis used to sort stations by rating so the order of stations with the same rating is not guaranteed and can differ between platforms so different stations receive leftover cargo causing desyncs. At least one platform is known to be affected so far (android): pelya/openttd-android#12Description
Replacing
std::sortwithstd::stable_sortshould fix the issue asused_stationsare guaranteed to b initially ordered by id due to std::set iteration.Checklist for review
Some things are not automated, and forgotten often. This list is a reminder for the reviewers.
This PR affects the save game format? (label 'savegame upgrade')This PR affects the GS/AI API? (label 'needs review: Script API')This PR affects the NewGRF API? (label 'needs review: NewGRF')