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

@@ -931,16 +931,17 @@ public function transactional(Closure $func): mixed
 
         try {
             $res = $func($this);
-            $this->commit();
 
             $successful = true;
-
-            return $res;
         } finally {
             if (! $successful) {
                 $this->rollBack();
             }
         }
+
+        $this->commit();
+
+        return $res;
     }
 
     /**
@@ -1019,16 +1020,23 @@ public function commit(): void
 
         $connection = $this->connect();
 
-        if ($this->transactionNestingLevel === 1) {
-            try {
-                $connection->commit();
-            } catch (Driver\Exception $e) {
-                throw $this->convertException($e);
+        try {
+            if ($this->transactionNestingLevel === 1) {
+                try {
+                    $connection->commit();
+                } catch (Driver\Exception $e) {
+                    throw $this->convertException($e);
+                }
+            } else {
+                $this->releaseSavepoint($this->_getNestedTransactionSavePointName());
             }
-        } else {
-            $this->releaseSavepoint($this->_getNestedTransactionSavePointName());
+        } finally {
+            $this->updateTransactionStateAfterCommit();
         }
+    }
 
+    private function updateTransactionStateAfterCommit(): void
+    {
         --$this->transactionNestingLevel;
 
         if ($this->autoCommit !== false || $this->transactionNestingLevel !== 0) {
@@ -1038,6 +1046,28 @@ public function commit(): void
         $this->beginTransaction();
     }
 
+    /**
+     * @return bool
+     *
+     * @throws DriverException
+     */
+    private function doCommit(DriverConnection $connection)
+    {
+        $logger = $this->_config->getSQLLogger();
+
+        if ($logger !== null) {
+            $logger->startQuery('"COMMIT"');
+        }
+
+        $result = $connection->commit();
+
+        if ($logger !== null) {
+            $logger->stopQuery();
+        }
+
+        return $result;
+    }
+
     /**
      * Commits all current nesting transactions.
      *

src/Driver/OCI8/Connection.php

@@ -95,7 +95,7 @@ public function beginTransaction(): void
 
     public function commit(): void
     {
-        if (! oci_commit($this->connection)) {
+        if (! @oci_commit($this->connection)) {
             throw Error::new($this->connection);
         }