Fix artifacts v4 backend upload problems (#36805)

* Use base64.RawURLEncoding to avoid equal sign
  * using the nodejs package they seem to get lost
* Support uploads with unspecified length
* Support uploads with a single named blockid
  * without requiring a blockmap

---------

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/storage/local_test.go

@@ -4,11 +4,14 @@
 package storage
 
 import (
+	"os"
+	"strings"
 	"testing"
 
 	"code.gitea.io/gitea/modules/setting"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestBuildLocalPath(t *testing.T) {
@@ -53,6 +56,49 @@ func TestBuildLocalPath(t *testing.T) {
 	}
 }
 
+func TestLocalStorageDelete(t *testing.T) {
+	rootDir := t.TempDir()
+	st, err := NewLocalStorage(t.Context(), &setting.Storage{Path: rootDir})
+	require.NoError(t, err)
+
+	assertExists := func(t *testing.T, path string, exists bool) {
+		_, err = os.Stat(rootDir + "/" + path)
+		if exists {
+			require.NoError(t, err)
+		} else {
+			require.ErrorIs(t, err, os.ErrNotExist)
+		}
+	}
+
+	_, err = st.Save("dir/sub1/1-a.txt", strings.NewReader(""), -1)
+	require.NoError(t, err)
+	_, err = st.Save("dir/sub1/1-b.txt", strings.NewReader(""), -1)
+	require.NoError(t, err)
+	_, err = st.Save("dir/sub2/2-a.txt", strings.NewReader(""), -1)
+	require.NoError(t, err)
+
+	assertExists(t, "dir/sub1/1-a.txt", true)
+	assertExists(t, "dir/sub1/1-b.txt", true)
+	assertExists(t, "dir/sub2/2-a.txt", true)
+
+	require.NoError(t, st.Delete("dir/sub1/1-a.txt"))
+	assertExists(t, "dir/sub1", true)
+	assertExists(t, "dir/sub1/1-a.txt", false)
+	assertExists(t, "dir/sub1/1-b.txt", true)
+	assertExists(t, "dir/sub2/2-a.txt", true)
+
+	require.NoError(t, st.Delete("dir/sub1/1-b.txt"))
+	assertExists(t, ".", true)
+	assertExists(t, "dir/sub1", false)
+	assertExists(t, "dir/sub1/1-a.txt", false)
+	assertExists(t, "dir/sub1/1-b.txt", false)
+	assertExists(t, "dir/sub2/2-a.txt", true)
+
+	require.NoError(t, st.Delete("dir/sub2/2-a.txt"))
+	assertExists(t, ".", true)
+	assertExists(t, "dir", false)
+}
+
 func TestLocalStorageIterator(t *testing.T) {
 	testStorageIterator(t, setting.LocalStorageType, &setting.Storage{Path: t.TempDir()})
 }