operations: Fix Purge and Rmdirs when dir is not empty

Before this change, Purge on the fallback path would try to delete
directories starting from the root rather than the dir passed in.
Rmdirs would also attempt to delete the root.

fs/operations/operations.go

@@ -975,7 +975,7 @@ func Purge(f fs.Fs, dir string) error {
 		if err != nil {
 			return err
 		}
-		err = Rmdirs(f, "", false)
+		err = Rmdirs(f, dir, false)
 	}
 	if err != nil {
 		fs.CountError(err)
@@ -1206,7 +1206,7 @@ func PublicLink(f fs.Fs, remote string) (string, error) {
 // containing empty directories) under f, including f.
 func Rmdirs(f fs.Fs, dir string, leaveRoot bool) error {
 	dirEmpty := make(map[string]bool)
-	dirEmpty[""] = !leaveRoot
+	dirEmpty[dir] = !leaveRoot
 	err := walk.Walk(f, dir, true, fs.Config.MaxDepth, func(dirPath string, entries fs.DirEntries, err error) error {
 		if err != nil {
 			fs.CountError(err)

fs/operations/operations_test.go

@@ -401,6 +401,78 @@ func TestRcat(t *testing.T) {
 	check(false)
 }
 
+func TestPurge(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+	r.Mkdir(r.Fremote)
+
+	// Make some files and dirs
+	r.ForceMkdir(r.Fremote)
+	file1 := r.WriteObject("A1/B1/C1/one", "aaa", t1)
+	//..and dirs we expect to delete
+	require.NoError(t, operations.Mkdir(r.Fremote, "A2"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A1/B2"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A1/B2/C2"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A1/B1/C3"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A3"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A3/B3"))
+	require.NoError(t, operations.Mkdir(r.Fremote, "A3/B3/C4"))
+	//..and one more file at the end
+	file2 := r.WriteObject("A1/two", "bbb", t2)
+
+	fstest.CheckListingWithPrecision(
+		t,
+		r.Fremote,
+		[]fstest.Item{
+			file1, file2,
+		},
+		[]string{
+			"A1",
+			"A1/B1",
+			"A1/B1/C1",
+			"A2",
+			"A1/B2",
+			"A1/B2/C2",
+			"A1/B1/C3",
+			"A3",
+			"A3/B3",
+			"A3/B3/C4",
+		},
+		fs.GetModifyWindow(r.Fremote),
+	)
+
+	require.NoError(t, operations.Purge(r.Fremote, "A1/B1"))
+
+	fstest.CheckListingWithPrecision(
+		t,
+		r.Fremote,
+		[]fstest.Item{
+			file2,
+		},
+		[]string{
+			"A1",
+			"A2",
+			"A1/B2",
+			"A1/B2/C2",
+			"A3",
+			"A3/B3",
+			"A3/B3/C4",
+		},
+		fs.GetModifyWindow(r.Fremote),
+	)
+
+	require.NoError(t, operations.Purge(r.Fremote, ""))
+
+	fstest.CheckListingWithPrecision(
+		t,
+		r.Fremote,
+		[]fstest.Item{},
+		[]string{},
+		fs.GetModifyWindow(r.Fremote),
+	)
+
+}
+
 func TestRmdirsNoLeaveRoot(t *testing.T) {
 	r := fstest.NewRun(t)
 	defer r.Finalise()
@@ -441,6 +513,28 @@ func TestRmdirsNoLeaveRoot(t *testing.T) {
 		fs.GetModifyWindow(r.Fremote),
 	)
 
+	require.NoError(t, operations.Rmdirs(r.Fremote, "A3/B3/C4", false))
+
+	fstest.CheckListingWithPrecision(
+		t,
+		r.Fremote,
+		[]fstest.Item{
+			file1, file2,
+		},
+		[]string{
+			"A1",
+			"A1/B1",
+			"A1/B1/C1",
+			"A2",
+			"A1/B2",
+			"A1/B2/C2",
+			"A1/B1/C3",
+			"A3",
+			"A3/B3",
+		},
+		fs.GetModifyWindow(r.Fremote),
+	)
+
 	require.NoError(t, operations.Rmdirs(r.Fremote, "", false))
 
 	fstest.CheckListingWithPrecision(