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A channel comparison bug when channels are used as case expressions of switch code blocks (in Go toolchain v1.20 - v1.23.x)

(The releatd issue: https://github.com/golang/go/issues/67190.)

In Go toolchain v1.20 - v1.23.x, there is a channel value comparison bug, which is demonstrated in the following program: 

// chan-cmp-bug.go
package main

import "fmt"

func main() {
	x := make(chan struct{})

	var y <-chan struct{} = x

	switch x {
	case y: fmt.Print(1)
	default: fmt.Print(0)
	}

	switch y {
	case x: fmt.Print(1)
	default: fmt.Print(0)
	}

	fmt.Println(x == y)
}

The program should print 11true. But it prints 01true with Go toolchain versions from v1.20 to v1.23.0 (exclusive). 

$ gotv 1.19. run chan-cmp-bug.go
[Run]: $HOME/.cache/gotv/tag_go1.19.13/bin/go run chan-cmp-bug.go
11true
$ gotv 1.20 run chan-cmp-bug.go
[Run]: $HOME/.cache/gotv/tag_go1.20/bin/go run chan-cmp-bug.go
01true
$ gotv 1.21. run chan-cmp-bug.go
[Run]: $HOME/.cache/gotv/tag_go1.21.12/bin/go run chan-cmp-bug.go
01true
$ gotv 1.22. run chan-cmp-bug.go
[Run]: $HOME/.cache/gotv/tag_go1.22.5/bin/go run chan-cmp-bug.go
01true
$ gotv 1.23.0 run chan-cmp-bug.go
[Run]: $HOME/.cache/gotv/tag_go1.23rc1/bin/go run chan-cmp-bug.go
11true

The bug started from Go toolchain version v1.20 and has been fixed since v1.23.0.

If you are using a Go toolchain version between v1.20 and v1.23.0 (exclusive), you should be aware of this bug.

(GoTV is a tool used to manage and use multiple coexisting installations of official Go toolchain versions harmoniously and conveniently.)

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