NetworksByPriority: ensure the sort order is stable #580
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Related to:
2.24.6
docker/compose#11510NetworksByPriority calls sort.Slice() to sort the map of networks attached to a given service by their respective priority. The Priority property being non mandatory, it defaults to 0 when unspecified.
The godoc for sort.Slice() specifies:
SliceStable() won't work either, since NetworksByPriority has to transform the map of networks into a list before calling sort.Slice() -- Go makes no guarantee about the order of items in a map.
The only way to guarantee a stable order is to fall back to lexicographic sorting when two networks have the same priority. It seems to be the best option as the compose-spec doesn't specify how multiple network attachment referencing the same network should be handled.
A regression test has been added.