Revert "SERVER-34441 error when aborting or commiting a nonexistent txn and starting a txn with one running"

This reverts commit 1c3d79e1c8eccb4fbc57f7a43e165b3f5b9409f0.

3 files changed, 25 insertions, 69 deletions

diff --git a/jstests/core/txns/multi_statement_transaction_using_api.js b/jstests/core/txns/multi_statement_transaction_using_api.js
index 1eb213d458f..ce0dfd96bbe 100644
--- a/jstests/core/txns/multi_statement_transaction_using_api.js
+++ b/jstests/core/txns/multi_statement_transaction_using_api.js
@@ -84,6 +84,26 @@
     // Verify that we cannot see the document we tried to insert.
     assert.eq(null, sessionColl.findOne({_id: "insert-4"}));
 
+    //
+    // Test that calling startTransaction when a transaction is already running aborts the
+    // current transaction.
+    //
+    jsTestLog("Call startTransaction before committing or aborting the current transaction.");
+    session.startTransaction({readConcern: {level: "snapshot"}, writeConcern: {w: "majority"}});
+
+    assert.commandWorked(sessionColl.insert({_id: "restart-txn-1"}));
+
+    // Try starting a new transaction without committing the previous one. This should result in
+    // the current transaction being implicitly aborted.
+    session.startTransaction({readConcern: {level: "snapshot"}, writeConcern: {w: "majority"}});
+
+    assert.commandWorked(sessionColl.insert({_id: "restart-txn-2"}));
+    session.commitTransaction();
+
+    // Make sure the correct documents exist after committing the second transaction.
+    assert.eq({_id: "restart-txn-2"}, sessionColl.findOne({_id: "restart-txn-2"}));
+    assert.eq(null, sessionColl.findOne({_id: "restart-txn-1"}));
+
     jsTestLog("Bulk insert and update operations within transaction.");
 
     session.startTransaction({readConcern: {level: "snapshot"}, writeConcern: {w: "majority"}});
diff --git a/jstests/core/txns/transaction_error_handling.js b/jstests/core/txns/transaction_error_handling.js
deleted file mode 100644
index d30e8c6003e..00000000000
--- a/jstests/core/txns/transaction_error_handling.js
+++ /dev/null
@@ -1,41 +0,0 @@
-// Test basic transaction error handling.
-// @tags: [uses_transactions]
-(function() {
-    "use strict";
-
-    const dbName = "test";
-    const collName = "transaction_error_handling";
-    const testDB = db.getSiblingDB(dbName);
-
-    testDB.runCommand({drop: collName, writeConcern: {w: "majority"}});
-
-    assert.commandWorked(testDB.runCommand({create: collName, writeConcern: {w: "majority"}}));
-
-    const sessionOptions = {causalConsistency: false};
-    const session = testDB.getMongo().startSession(sessionOptions);
-    const sessionDb = session.getDatabase(dbName);
-    const sessionColl = sessionDb.getCollection(collName);
-
-    // Cannot abort or commit a nonexistant transaction.
-    try {
-        session.commitTransaction();
-    } catch (e) {
-        assert.eq(e.message, "There is no active transaction to commit on this session.");
-    }
-
-    try {
-        session.abortTransaction();
-    } catch (e) {
-        assert.eq(e.message, "There is no active transaction to abort on this session.");
-    }
-
-    // Try to start a transaction with one already running.
-    session.startTransaction();
-    try {
-        session.startTransaction();
-    } catch (e) {
-        assert.eq(e.message, "Transaction already in progress on this session.");
-    }
-
-    session.endSession();
-}());
diff --git a/src/mongo/shell/session.js b/src/mongo/shell/session.js
index bf414d160a4..08bce40b94d 100644
--- a/src/mongo/shell/session.js
+++ b/src/mongo/shell/session.js
@@ -700,10 +700,6 @@ var {
         };
 
         this.startTransaction = function startTransaction(txnOptsObj) {
-            // If the session is already in a transaction, raise an error.
-            if (this.isInActiveTransaction()) {
-                throw new Error("Transaction already in progress on this session.");
-            }
             _txnOptions = new TransactionOptions(txnOptsObj);
             _txnState = ServerSession.TransactionStates.kActive;
             _nextStatementId = 0;
@@ -711,19 +707,11 @@ var {
         };
 
         this.commitTransaction = function commitTransaction(driverSession) {
-            // If the session has no active transaction, raise an error.
-            if (!this.isInActiveTransaction()) {
-                throw new Error("There is no active transaction to commit on this session.");
-            }
             // run commitTxn command
             return endTransaction("commitTransaction", driverSession);
         };
 
         this.abortTransaction = function abortTransaction(driverSession) {
-            // If the session has no active transaction, raise an error.
-            if (!this.isInActiveTransaction()) {
-                throw new Error("There is no active transaction to abort on this session.");
-            }
             // run abortTxn command
             return endTransaction("abortTransaction", driverSession);
         };
@@ -738,25 +726,13 @@ var {
             }
 
             let cmd = {[commandName]: 1, txnNumber: NumberLong(_txnNumber)};
-            // writeConcern should only be specified on commit or abort. If a writeConcern is
-            // not specified from the default transaction options, it will be inherited from
-            // the session.
-            if (this.client.getWriteConcern(driverSession) !== undefined) {
-                cmd.writeConcern = this.client.getWriteConcern(driverSession);
-            }
+            // writeConcern should only be specified on commit or abort
             if (_txnOptions.getTxnWriteConcern() !== undefined) {
                 cmd.writeConcern = _txnOptions.getTxnWriteConcern();
             }
-
-            // If commit or abort raises an error, the transaction's state should still change
-            // to inactive.
-            let res;
-            try {
-                // run command against the admin database.
-                res = this.client.runCommand(driverSession, "admin", cmd, 0);
-            } finally {
-                _txnState = ServerSession.TransactionStates.kInactive;
-            }
+            // run command against the admin database.
+            const res = this.client.runCommand(driverSession, "admin", cmd, 0);
+            _txnState = ServerSession.TransactionStates.kInactive;
             return res;
         };
     }
@@ -880,6 +856,7 @@ var {
                 // Intentionally ignore command result.
                 this._serverSession.abortTransaction(this);
             };
+
             this.commitTransaction_forTesting = function commitTransaction_forTesting() {
                 return this._serverSession.commitTransaction(this);
             };