fix(transactions): don't use CLS on manually manged transactions (#8430)

lib/sequelize.js

@@ -962,7 +962,7 @@ class Sequelize {
 
     const transaction = new Transaction(this, options);
 
-    if (!autoCallback) return transaction.prepareEnvironment().return(transaction);
+    if (!autoCallback) return transaction.prepareEnvironment(false).return(transaction);
 
     // autoCallback provided
     return Sequelize._clsRun(() => {

lib/transaction.js

@@ -99,9 +99,13 @@ class Transaction {
       });
   }
 
-  prepareEnvironment() {
+  prepareEnvironment(useCLS) {
     let connectionPromise;
 
+    if (typeof useCLS === 'undefined') {
+      useCLS = true;
+    }
+
     if (this.parent) {
       connectionPromise = Utils.Promise.resolve(this.parent.connection);
     } else {
@@ -125,7 +129,7 @@ class Transaction {
         throw setupErr;
       }))
       .tap(() => {
-        if (this.sequelize.constructor._cls) {
+        if (useCLS && this.sequelize.constructor._cls) {
           this.sequelize.constructor._cls.set('transaction', this);
         }
         return null;

test/integration/cls.test.js

@@ -33,6 +33,17 @@ if (current.dialect.supports.transactions) {
     });
 
     describe('context', () => {
+      it('does not use continuation storage on manually managed transactions', function() {
+        const self = this;
+
+        return Sequelize._clsRun(() => {
+          return this.sequelize.transaction().then(transaction => {
+            expect(self.ns.get('transaction')).to.be.undefined;
+            return transaction.rollback();
+          });
+        });
+      });
+
       it('supports several concurrent transactions', function() {
         let t1id, t2id;
         const self = this;