Merge branch '3.4' into 4.4

* 3.4:
  updated VERSION for 3.4.40
  update CONTRIBUTORS for 3.4.40
  updated CHANGELOG for 3.4.40
  [WebProfilerBundle] changed label of peak memory usage in the time & memory panels (MB into MiB)
  add tests for the ConstraintViolationBuilder class
  Improve dirname usage
  [PhpUnitBridge] Use COMPOSER_BINARY env var if available
  [YAML] escape DEL(\x7f)
  fix compatibility with phpunit 9
  [Cache] skip APCu in chains when the backend is disabled
  [Form] apply automatically step=1 for datetime-local input

Author: nicolas-grekas

Extension/Core/Type/DateTimeType.php

@@ -218,6 +218,14 @@ public function buildView(FormView $view, FormInterface $form, array $options)
         //  * the html5 is set to true
         if ($options['html5'] && 'single_text' === $options['widget'] && self::HTML5_FORMAT === $options['format']) {
             $view->vars['type'] = 'datetime-local';
+
+            // we need to force the browser to display the seconds by
+            // adding the HTML attribute step if not already defined.
+            // Otherwise the browser will not display and so not send the seconds
+            // therefore the value will always be considered as invalid.
+            if ($options['with_seconds'] && !isset($view->vars['attr']['step'])) {
+                $view->vars['attr']['step'] = 1;
+            }
         }
     }
 

Tests/Extension/Core/Type/DateTimeTypeTest.php

@@ -495,6 +495,37 @@ public function testDontPassHtml5TypeIfNotSingleText()
         $this->assertArrayNotHasKey('type', $view->vars);
     }
 
+    public function testSingleTextWidgetWithSecondsShouldHaveRightStepAttribute()
+    {
+        $view = $this->factory
+            ->create(static::TESTED_TYPE, null, [
+                'widget' => 'single_text',
+                'with_seconds' => true,
+            ])
+            ->createView()
+        ;
+
+        $this->assertArrayHasKey('step', $view->vars['attr']);
+        $this->assertEquals(1, $view->vars['attr']['step']);
+    }
+
+    public function testSingleTextWidgetWithSecondsShouldNotOverrideStepAttribute()
+    {
+        $view = $this->factory
+            ->create(static::TESTED_TYPE, null, [
+                'widget' => 'single_text',
+                'with_seconds' => true,
+                'attr' => [
+                    'step' => 30,
+                ],
+            ])
+            ->createView()
+        ;
+
+        $this->assertArrayHasKey('step', $view->vars['attr']);
+        $this->assertEquals(30, $view->vars['attr']['step']);
+    }
+
     public function testSingleTextWidgetWithCustomNonHtml5Format()
     {
         $form = $this->factory->create(static::TESTED_TYPE, new \DateTime('2019-02-13 19:12:13'), [