meta: clone table info with new foreign keys default to nil (#60103)

close #60044

Author: River2000i

pkg/meta/meta_test.go

@@ -706,6 +706,23 @@ func TestIsTableInfoMustLoad(t *testing.T) {
 	require.NoError(t, err)
 	require.True(t, meta.IsTableInfoMustLoad(b))
 
+	tableInfo = tableInfo.Clone()
+	b, err = json.Marshal(tableInfo)
+	require.NoError(t, err)
+	require.True(t, meta.IsTableInfoMustLoad(b))
+
+	tableInfo.ForeignKeys = nil
+	tableInfo = tableInfo.Clone()
+	b, err = json.Marshal(tableInfo)
+	require.NoError(t, err)
+	require.False(t, meta.IsTableInfoMustLoad(b))
+
+	tableInfo.ForeignKeys = make([]*model.FKInfo, 0)
+	tableInfo = tableInfo.Clone()
+	b, err = json.Marshal(tableInfo)
+	require.NoError(t, err)
+	require.False(t, meta.IsTableInfoMustLoad(b))
+
 	tableInfo = &model.TableInfo{
 		TempTableType: model.TempTableGlobal,
 		State:         model.StatePublic,

pkg/meta/model/table.go

@@ -242,7 +242,7 @@ func (t *TableInfo) Clone() *TableInfo {
 	nt := *t
 	nt.Columns = make([]*ColumnInfo, len(t.Columns))
 	nt.Indices = make([]*IndexInfo, len(t.Indices))
-	nt.ForeignKeys = make([]*FKInfo, len(t.ForeignKeys))
+	nt.ForeignKeys = nil
 
 	for i := range t.Columns {
 		nt.Columns[i] = t.Columns[i].Clone()
@@ -252,8 +252,11 @@ func (t *TableInfo) Clone() *TableInfo {
 		nt.Indices[i] = t.Indices[i].Clone()
 	}
 
-	for i := range t.ForeignKeys {
-		nt.ForeignKeys[i] = t.ForeignKeys[i].Clone()
+	if len(t.ForeignKeys) > 0 {
+		nt.ForeignKeys = make([]*FKInfo, len(t.ForeignKeys))
+		for i := range t.ForeignKeys {
+			nt.ForeignKeys[i] = t.ForeignKeys[i].Clone()
+		}
 	}
 
 	if t.Partition != nil {