sort() behaves different in Linux & Windows

[malisipi]

Describe the bug

Sort function sorts different in different operating systems.

Expected Behavior

Same behavior in all operating systems.

Current Behavior

Linux Output

[Post{
    name: 'C'
    like: 5
}, Post{
    name: 'A'
    like: 4
}, Post{
    name: 'B'
    like: 4
}]

Windows Output

[Post{
    name: 'C'
    like: 5
}, Post{
    name: 'B'
    like: 4
}, Post{
    name: 'A'
    like: 4
}]

Reproduction Steps

struct Post {
	name	string
	like	int
}

mut posts := [Post{name: "B", like:4},Post{name: "A", like:4}, Post{name:"C", like:5}]

posts.sort(a.like > b.like)

println(posts)

Possible Solution

No response

Additional Information/Context

No response

V version

V 0.3.2 a987f84

Environment details (OS name and version, etc.)

Ubuntu 22.10 (x86_64) & Windows 10 Home (x86_64)

[kbkpbot]

man qsort :
If two members compare as equal, their order in the sorted array is undefined.

I guess glibc use a mergesort instead of quicksort.

https://stackoverflow.com/questions/33975642/force-c-library-qsort-to-perform-a-quicksort-rather-than-a-mergesort
https://stackoverflow.com/questions/31518282/how-to-leave-ordering-unchanged-on-equality-using-qsort

[larpon]

I have observed the same while implementing a z-based renderer that used sort() there was flickering on e.g. Android where items had the same z value that was sorted by - that flickering does not appear on Linux where the implementation is different