Fix incorrect handling of transactions when using deferred constraints

Let's get rid of There's no active transaction exception which occurs e.g. when using deferred constraints so the violation is checked at the end of the transaction and not during it.

Author: simPod

src/Connection.php

@@ -1283,16 +1283,17 @@ public function transactional(Closure $func)
 
         try {
             $res = $func($this);
-            $this->commit();
 
             $successful = true;
-
-            return $res;
         } finally {
             if (! $successful) {
                 $this->rollBack();
             }
         }
+
+        $this->commit();
+
+        return $res;
     }
 
     /**
@@ -1424,12 +1425,21 @@ public function commit()
 
         $connection = $this->getWrappedConnection();
 
-        if ($this->transactionNestingLevel === 1) {
-            $result = $this->doCommit($connection);
-        } elseif ($this->nestTransactionsWithSavepoints) {
-            $this->releaseSavepoint($this->_getNestedTransactionSavePointName());
+        try {
+            if ($this->transactionNestingLevel === 1) {
+                $result = $this->doCommit($connection);
+            } elseif ($this->nestTransactionsWithSavepoints) {
+                $this->releaseSavepoint($this->_getNestedTransactionSavePointName());
+            }
+        } finally {
+            $this->updateTransactionStateAfterCommit();
         }
 
+        return $result;
+    }
+
+    private function updateTransactionStateAfterCommit(): void
+    {
         --$this->transactionNestingLevel;
 
         $eventManager = $this->getEventManager();
@@ -1446,12 +1456,10 @@ public function commit()
         }
 
         if ($this->autoCommit !== false || $this->transactionNestingLevel !== 0) {
-            return $result;
+            return;
         }
 
         $this->beginTransaction();
-
-        return $result;
     }
 
     /**

src/Driver/OCI8/Connection.php

@@ -142,7 +142,7 @@ public function beginTransaction(): bool
 
     public function commit(): bool
     {
-        if (! oci_commit($this->connection)) {
+        if (! @oci_commit($this->connection)) {
             throw Error::new($this->connection);
         }