fs: add --ignore-case-sync for forced case insensitivity - fixes #2773

docs/content/docs.md

@@ -500,6 +500,12 @@ Do a trial run with no permanent changes.  Use this to see what rclone
 would do without actually doing it.  Useful when setting up the `sync`
 command which deletes files in the destination.
 
+### --ignore-case-sync ###
+
+Using this option will cause rclone to ignore the case of the files 
+when synchronizing so files will not be copied/synced when the
+existing filenames are the same, even if the casing is different.
+
 ### --ignore-checksum ###
 
 Normally rclone will check that the checksums of transferred files

fs/config.go

@@ -62,6 +62,7 @@ type ConfigInfo struct {
 	MaxDepth               int
 	IgnoreSize             bool
 	IgnoreChecksum         bool
+	IgnoreCaseSync         bool
 	NoTraverse             bool
 	NoUpdateModTime        bool
 	DataRateUnit           string

fs/config/configflags/configflags.go

@@ -64,6 +64,7 @@ func AddFlags(flagSet *pflag.FlagSet) {
 	flags.IntVarP(flagSet, &fs.Config.MaxDepth, "max-depth", "", fs.Config.MaxDepth, "If set limits the recursion depth to this.")
 	flags.BoolVarP(flagSet, &fs.Config.IgnoreSize, "ignore-size", "", false, "Ignore size when skipping use mod-time or checksum.")
 	flags.BoolVarP(flagSet, &fs.Config.IgnoreChecksum, "ignore-checksum", "", fs.Config.IgnoreChecksum, "Skip post copy check of checksums.")
+	flags.BoolVarP(flagSet, &fs.Config.IgnoreCaseSync, "ignore-case-sync", "", fs.Config.IgnoreCaseSync, "Ignore case when synchronizing")
 	flags.BoolVarP(flagSet, &fs.Config.NoTraverse, "no-traverse", "", fs.Config.NoTraverse, "Don't traverse destination file system on copy.")
 	flags.BoolVarP(flagSet, &fs.Config.NoUpdateModTime, "no-update-modtime", "", fs.Config.NoUpdateModTime, "Don't update destination mod-time if files identical.")
 	flags.StringVarP(flagSet, &fs.Config.BackupDir, "backup-dir", "", fs.Config.BackupDir, "Make backups into hierarchy based in DIR.")

fs/march/march.go

@@ -58,7 +58,7 @@ func (m *March) init() {
 	//                  | Yes | No  | No                 |
 	//                  | No  | Yes | Yes                |
 	//                  | Yes | Yes | Yes                |
-	if m.Fdst.Features().CaseInsensitive {
+	if m.Fdst.Features().CaseInsensitive || fs.Config.IgnoreCaseSync {
 		m.transforms = append(m.transforms, strings.ToLower)
 	}
 }

fs/sync/sync_test.go

@@ -1346,6 +1346,33 @@ func TestSyncImmutable(t *testing.T) {
 	fstest.CheckItems(t, r.Fremote, file1)
 }
 
+// Test --ignore-case-sync
+func TestSyncIgnoreCase(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+
+	// Only test if filesystems are case sensitive
+	if r.Fremote.Features().CaseInsensitive || r.Flocal.Features().CaseInsensitive {
+		t.Skip("Skipping test as local or remote are case-insensitive")
+	}
+
+	fs.Config.IgnoreCaseSync = true
+	defer func() { fs.Config.IgnoreCaseSync = false }()
+
+	// Create files with different filename casing
+	file1 := r.WriteFile("existing", "potato", t1)
+	fstest.CheckItems(t, r.Flocal, file1)
+	file2 := r.WriteObject("EXISTING", "potato", t1)
+	fstest.CheckItems(t, r.Fremote, file2)
+
+	// Should not copy files that are differently-cased but otherwise identical
+	accounting.Stats.ResetCounters()
+	err := Sync(r.Fremote, r.Flocal, false)
+	require.NoError(t, err)
+	fstest.CheckItems(t, r.Flocal, file1)
+	fstest.CheckItems(t, r.Fremote, file2)
+}
+
 // Test that aborting on max upload works
 func TestAbort(t *testing.T) {
 	r := fstest.NewRun(t)