lib/config, lib/fs: Make junction behaviour configurable (ref #6606) (#6907)

lib/config/config.go

@@ -31,7 +31,7 @@ import (
 
 const (
 	OldestHandledVersion = 10
-	CurrentVersion       = 31
+	CurrentVersion       = 32
 	MaxRescanIntervalS   = 365 * 24 * 60 * 60
 )
 

lib/config/config_test.go

@@ -126,6 +126,7 @@ func TestDeviceConfig(t *testing.T) {
 				},
 				WeakHashThresholdPct: 25,
 				MarkerName:           DefaultMarkerName,
+				JunctionsAsDirs:      true,
 			},
 		}
 

lib/config/folderconfiguration.go

@@ -62,6 +62,7 @@ type FolderConfiguration struct {
 	BlockPullOrder          BlockPullOrder              `xml:"blockPullOrder" json:"blockPullOrder"`
 	CopyRangeMethod         fs.CopyRangeMethod          `xml:"copyRangeMethod" json:"copyRangeMethod" default:"standard"`
 	CaseSensitiveFS         bool                        `xml:"caseSensitiveFS" json:"caseSensitiveFS"`
+	JunctionsAsDirs         bool                        `xml:"junctionsAsDirs" json:"junctionsAsDirs"`
 
 	cachedModTimeWindow time.Duration
 
@@ -101,7 +102,11 @@ func (f FolderConfiguration) Copy() FolderConfiguration {
 func (f FolderConfiguration) Filesystem() fs.Filesystem {
 	// This is intentionally not a pointer method, because things like
 	// cfg.Folders["default"].Filesystem() should be valid.
-	filesystem := fs.NewFilesystem(f.FilesystemType, f.Path)
+	var opts []fs.Option
+	if f.FilesystemType == fs.FilesystemTypeBasic && f.JunctionsAsDirs {
+		opts = append(opts, fs.WithJunctionsAsDirs())
+	}
+	filesystem := fs.NewFilesystem(f.FilesystemType, f.Path, opts...)
 	if !f.CaseSensitiveFS {
 		filesystem = fs.NewCaseFilesystem(filesystem)
 	}

lib/config/migrations.go

@@ -25,6 +25,7 @@ import (
 // update the config version. The order of migrations doesn't matter here,
 // put the newest on top for readability.
 var migrations = migrationSet{
+	{32, migrateToConfigV32},
 	{31, migrateToConfigV31},
 	{30, migrateToConfigV30},
 	{29, migrateToConfigV29},
@@ -91,6 +92,12 @@ func migrateToConfigV31(cfg *Configuration) {
 	cfg.Options.UnackedNotificationIDs = append(cfg.Options.UnackedNotificationIDs, "authenticationUserAndPassword")
 }
 
+func migrateToConfigV32(cfg *Configuration) {
+	for i := range cfg.Folders {
+		cfg.Folders[i].JunctionsAsDirs = true
+	}
+}
+
 func migrateToConfigV30(cfg *Configuration) {
 	// The "max concurrent scans" option is now spelled "max folder concurrency"
 	// to be more general.