Issue #2871004 by mondrake: Add a test for INSERTing invalid data fetched from a subselect query

core/tests/Drupal/KernelTests/Core/Database/InvalidDataTest.php

@@ -66,4 +66,81 @@ class InvalidDataTest extends DatabaseTestBase {
     }
   }
 
+  /**
+   * Tests inserting with invalid data from a select query.
+   */
+  public function testInsertDuplicateDataFromSelect() {
+    // Insert multiple records in 'test_people' where one has bad data
+    // (duplicate key). A 'Meredith' record has already been inserted
+    // in ::setUp.
+    db_insert('test_people')
+      ->fields(['name', 'age', 'job'])
+      ->values([
+        'name' => 'Elvis',
+        'age' => 63,
+        'job' => 'Singer',
+      ])->values([
+        // Duplicate value on unique field 'name' for later INSERT in 'test'
+        // table.
+        'name' => 'John',
+        'age' => 17,
+        'job' => 'Consultant',
+      ])
+      ->values([
+        'name' => 'Frank',
+        'age' => 75,
+        'job' => 'Bass',
+      ])
+      ->execute();
+
+    try {
+      // Define the subselect query. Add ORDER BY to ensure we have consistent
+      // order in results. Will return:
+      // 0 => [name] => Elvis, [age] => 63, [job] => Singer
+      // 1 => [name] => Frank, [age] => 75, [job] => Bass
+      // 2 => [name] => John, [age] => 17, [job] => Consultant
+      // 3 => [name] => Meredith, [age] => 30, [job] => Speaker
+      // Records 0 and 1 should pass, record 2 should lead to integrity
+      // constraint violation.
+      $query = db_select('test_people', 'tp')
+        ->fields('tp', ['name', 'age', 'job'])
+        ->orderBy('name');
+
+      // Try inserting from the subselect.
+      db_insert('test')
+        ->from($query)
+        ->execute();
+
+      $this->fail('Insert succeeded when it should not have.');
+    }
+    catch (IntegrityConstraintViolationException $e) {
+      // Check if the second record was inserted.
+      $name = db_query('SELECT name FROM {test} WHERE age = :age', [':age' => 75])->fetchField();
+
+      if ($name == 'Frank') {
+        if (!Database::getConnection()->supportsTransactions()) {
+          // This is an expected fail.
+          // Database engines that don't support transactions can leave partial
+          // inserts in place when an error occurs. This is the case for MySQL
+          // when running on a MyISAM table.
+          $this->pass("The whole transaction has not been rolled-back when a duplicate key insert occurs, this is expected because the database doesn't support transactions");
+        }
+        else {
+          $this->fail('The whole transaction is rolled back when a duplicate key insert occurs.');
+        }
+      }
+      else {
+        $this->pass('The whole transaction is rolled back when a duplicate key insert occurs.');
+      }
+
+      // Ensure the values for records 2 and 3 were not inserted.
+      $record = db_select('test')
+        ->fields('test', ['name', 'age'])
+        ->condition('age', [17, 30], 'IN')
+        ->execute()->fetchObject();
+
+      $this->assertFalse($record, 'The rest of the insert aborted as expected.');
+    }
+  }
+
 }