Fix stack overflow

join_table.go

@@ -13,12 +13,36 @@ type JoinTableHandlerInterface interface {
 	JoinWith(db *DB, source interface{}) *DB
 }
 
-type JoinTableSource struct {
-	ModelType   reflect.Type
-	ForeignKeys []struct {
+type JoinTableForeignKey struct {
 	DBName            string
 	AssociationDBName string
 }
+
+func updateJoinTableHandler(relationship *Relationship) {
+	handler := relationship.JoinTableHandler.(*JoinTableHandler)
+
+	destinationScope := &Scope{Value: reflect.New(handler.Destination.ModelType).Interface()}
+	for _, primaryField := range destinationScope.GetModelStruct().PrimaryFields {
+		db := relationship.ForeignDBName
+		handler.Destination.ForeignKeys = append(handler.Destination.ForeignKeys, JoinTableForeignKey{
+			DBName:            db,
+			AssociationDBName: primaryField.DBName,
+		})
+	}
+
+	sourceScope := &Scope{Value: reflect.New(handler.Source.ModelType).Interface()}
+	for _, primaryField := range sourceScope.GetModelStruct().PrimaryFields {
+		db := relationship.AssociationForeignDBName
+		handler.Source.ForeignKeys = append(handler.Source.ForeignKeys, JoinTableForeignKey{
+			DBName:            db,
+			AssociationDBName: primaryField.DBName,
+		})
+	}
+}
+
+type JoinTableSource struct {
+	ModelType   reflect.Type
+	ForeignKeys []JoinTableForeignKey
 }
 
 type JoinTableHandler struct {

model_struct.go

@@ -146,6 +146,7 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 		}
 	}
 
+	defer func() {
 		for _, field := range fields {
 			if !field.IsIgnored {
 				fieldStruct := field.Struct
@@ -205,8 +206,6 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 
 							if many2many := gormSettings["MANY2MANY"]; many2many != "" {
 								relationship.Kind = "many_to_many"
-							relationship.JoinTableHandler = JoinTableHandler{}
-
 								associationForeignKey := gormSettings["ASSOCIATIONFOREIGNKEY"]
 								if associationForeignKey == "" {
 									associationForeignKey = elemType.Name() + "Id"
@@ -216,6 +215,13 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 								relationship.ForeignDBName = ToDBName(foreignKey)
 								relationship.AssociationForeignFieldName = associationForeignKey
 								relationship.AssociationForeignDBName = ToDBName(associationForeignKey)
+								relationship.JoinTableHandler = &JoinTableHandler{
+									TableName:   many2many,
+									Source:      JoinTableSource{ModelType: scopeType},
+									Destination: JoinTableSource{ModelType: elemType},
+								}
+								updateJoinTableHandler(relationship)
+
 								field.Relationship = relationship
 							} else {
 								relationship.Kind = "has_many"
@@ -283,6 +289,7 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 			}
 			modelStruct.StructFields = append(modelStruct.StructFields, field)
 		}
+	}()
 
 	modelStructs[scopeType] = &modelStruct