build: use Go 1.23, require minimum 1.22 (#9651)

🥳

---------

Co-authored-by: Ross Smith II <ross@smithii.com>

.github/workflows/build-infra-dockers.yaml

@@ -7,7 +7,7 @@ on:
       - infra-*
 
 env:
-  GO_VERSION: "~1.22.3"
+  GO_VERSION: "~1.23.0"
   CGO_ENABLED: "0"
   BUILD_USER: docker
   BUILD_HOST: github.syncthing.net

.github/workflows/build-syncthing.yaml

@@ -12,7 +12,7 @@ env:
   # The go version to use for builds. We set check-latest to true when
   # installing, so we get the latest patch version that matches the
   # expression.
-  GO_VERSION: "~1.22.3"
+  GO_VERSION: "~1.23.0"
 
   # Optimize compatibility on the slow archictures.
   GO386: softfloat
@@ -48,7 +48,7 @@ jobs:
         runner: ["windows-latest", "ubuntu-latest", "macos-latest"]
         # The oldest version in this list should match what we have in our go.mod.
         # Variables don't seem to be supported here, or we could have done something nice.
-        go: ["~1.21.7", "~1.22.3"]
+        go: ["~1.22.6", "~1.23.0"]
     runs-on: ${{ matrix.runner }}
     steps:
       - name: Set git to use LF

go.mod

@@ -1,6 +1,6 @@
 module github.com/syncthing/syncthing
 
-go 1.21.0
+go 1.22.0
 
 require (
 	github.com/AudriusButkevicius/recli v0.0.7-0.20220911121932-d000ce8fbf0f

lib/fs/basicfs_lstat_windows.go

@@ -11,15 +11,15 @@ package fs
 
 import (
 	"fmt"
+	"go/version"
 	"os"
+	"runtime"
 	"syscall"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
 )
 
-const IO_REPARSE_TAG_DEDUP = 0x80000013
-
 func readReparseTag(path string) (uint32, error) {
 	namep, err := syscall.UTF16PtrFromString(path)
 	if err != nil {
@@ -60,10 +60,6 @@ func isDirectoryJunction(reparseTag uint32) bool {
 	return reparseTag == windows.IO_REPARSE_TAG_MOUNT_POINT
 }
 
-func isDeduplicatedFile(reparseTag uint32) bool {
-	return reparseTag == IO_REPARSE_TAG_DEDUP
-}
-
 type dirJunctFileInfo struct {
 	os.FileInfo
 }
@@ -71,21 +67,22 @@ type dirJunctFileInfo struct {
 func (fi *dirJunctFileInfo) Mode() os.FileMode {
 	// Simulate a directory and not a symlink; also set the execute
 	// bits so the directory can be traversed Unix-side.
-	return fi.FileInfo.Mode() ^ os.ModeSymlink | os.ModeDir | 0111
+	return fi.FileInfo.Mode() ^ junctionPointModeMask | os.ModeDir | 0111
 }
 
 func (fi *dirJunctFileInfo) IsDir() bool {
 	return true
 }
 
-type dedupFileInfo struct {
-	os.FileInfo
-}
+var junctionPointModeMask os.FileMode
 
-func (fi *dedupFileInfo) Mode() os.FileMode {
-	// A deduplicated file should be treated as a regular file and not an
-	// irregular file.
-	return fi.FileInfo.Mode() &^ os.ModeIrregular
+func init() {
+	junctionPointModeMask = os.ModeSymlink
+	if version.Compare(runtime.Version(), "go1.23") >= 0 {
+		// if GODEBUG=winsymlink=0, then we are in g1.22 mode so let's check for
+		// os.ModeSymlink as well, as it can't hurt.
+		junctionPointModeMask |= os.ModeIrregular
+	}
 }
 
 func (f *BasicFilesystem) underlyingLstat(name string) (os.FileInfo, error) {
@@ -96,19 +93,11 @@ func (f *BasicFilesystem) underlyingLstat(name string) (os.FileInfo, error) {
 	if err == nil {
 		// NTFS directory junctions can be treated as ordinary directories,
 		// see https://forum.syncthing.net/t/option-to-follow-directory-junctions-symbolic-links/14750
-		if fi.Mode()&os.ModeSymlink != 0 && f.junctionsAsDirs {
+		if fi.Mode()&junctionPointModeMask != 0 && f.junctionsAsDirs {
 			if reparseTag, reparseErr := readReparseTag(name); reparseErr == nil && isDirectoryJunction(reparseTag) {
 				return &dirJunctFileInfo{fi}, nil
 			}
 		}
-
-		// Workaround for #9120 till golang properly handles deduplicated files by
-		// considering them regular files.
-		if fi.Mode()&os.ModeIrregular != 0 {
-			if reparseTag, reparseErr := readReparseTag(name); reparseErr == nil && isDeduplicatedFile(reparseTag) {
-				return &dedupFileInfo{fi}, nil
-			}
-		}
 	}
 
 	return fi, err