[Form] fix edge cases with choice placeholder

src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig

@@ -52,7 +52,7 @@
 {%- endblock choice_widget_expanded -%}
 
 {%- block choice_widget_collapsed -%}
-    {%- if required and placeholder is none and not placeholder_in_choices and not multiple -%}
+    {%- if required and placeholder is none and not placeholder_in_choices and not multiple and (attr.size is not defined or attr.size <= 1) -%}
         {% set required = false %}
     {%- endif -%}
     <select {{ block('widget_attributes') }}{% if multiple %} multiple="multiple"{% endif %}>

src/Symfony/Bundle/FrameworkBundle/Resources/views/Form/choice_widget_collapsed.html.php

@@ -1,5 +1,5 @@
 <select
-    <?php if ($required && null === $placeholder && $placeholder_in_choices === false && $multiple === false):
+    <?php if ($required && null === $placeholder && $placeholder_in_choices === false && $multiple === false && (!isset($attr['size']) || $attr['size'] <= 1)):
         $required = false;
     endif; ?>
     <?php echo $view['form']->block($form, 'widget_attributes', array(

src/Symfony/Component/Form/ChoiceList/Factory/DefaultChoiceListFactory.php

@@ -246,7 +246,7 @@ class DefaultChoiceListFactory implements ChoiceListFactoryInterface
 
         $groupLabel = (string) $groupLabel;
 
-        // Initialize the group views if necessary. Unnnecessarily built group
+        // Initialize the group views if necessary. Unnecessarily built group
         // views will be cleaned up at the end of createView()
         if (!isset($preferredViews[$groupLabel])) {
             $preferredViews[$groupLabel] = new ChoiceGroupView($groupLabel);

src/Symfony/Component/Form/ChoiceList/View/ChoiceListView.php

@@ -48,4 +48,24 @@ class ChoiceListView
         $this->choices = $choices;
         $this->preferredChoices = $preferredChoices;
     }
+
+    /**
+     * Returns whether a placeholder is in the choices.
+     *
+     * A placeholder must be the first child element, not be in a group and have an empty value.
+     *
+     * @return bool
+     */
+    public function hasPlaceholder()
+    {
+        if ($this->preferredChoices) {
+            $firstChoice = reset($this->preferredChoices);
+
+            return $firstChoice instanceof ChoiceView && '' === $firstChoice->value;
+        }
+
+        $firstChoice = reset($this->choices);
+
+        return $firstChoice instanceof ChoiceView && '' === $firstChoice->value;
+    }
 }

src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php

@@ -199,7 +199,7 @@ class ChoiceType extends AbstractType
         }
 
         // Check if the choices already contain the empty value
-        $view->vars['placeholder_in_choices'] = 0 !== count($options['choice_list']->getChoicesForValues(array('')));
+        $view->vars['placeholder_in_choices'] = $choiceListView->hasPlaceholder();
 
         // Only add the empty value option if this is not the case
         if (null !== $options['placeholder'] && !$view->vars['placeholder_in_choices']) {
@@ -343,6 +343,9 @@ class ChoiceType extends AbstractType
             if ($options['multiple']) {
                 // never use an empty value for this case
                 return;
+            } elseif ($options['required'] && ($options['expanded'] || isset($options['attr']['size']) && $options['attr']['size'] > 1)) {
+                // placeholder for required radio buttons or a select with size > 1 does not make sense
+                return;
             } elseif (false === $placeholder) {
                 // an empty value should be added but the user decided otherwise
                 return;

src/Symfony/Component/Form/Tests/AbstractBootstrap3LayoutTest.php

@@ -232,6 +232,26 @@ abstract class AbstractBootstrap3LayoutTest extends AbstractLayoutTest
         );
     }
 
+    public function testSelectWithSizeBiggerThanOneCanBeRequired()
+    {
+        $form = $this->factory->createNamed('name', 'choice', null, array(
+            'choices' => array('a', 'b'),
+            'choices_as_values' => true,
+            'multiple' => false,
+            'expanded' => false,
+            'attr' => array('size' => 2),
+        ));
+
+        $this->assertWidgetMatchesXpath($form->createView(), array('attr' => array('class' => '')),
+'/select
+    [@name="name"]
+    [@required="required"]
+    [@size="2"]
+    [count(./option)=2]
+'
+        );
+    }
+
     public function testSingleChoiceWithoutTranslation()
     {
         $form = $this->factory->createNamed('name', 'choice', '&a', array(
@@ -754,6 +774,7 @@ abstract class AbstractBootstrap3LayoutTest extends AbstractLayoutTest
             'multiple' => false,
             'expanded' => true,
             'placeholder' => 'Test&Me',
+            'required' => false,
         ));
 
         $this->assertWidgetMatchesXpath($form->createView(), array(),

src/Symfony/Component/Form/Tests/AbstractLayoutTest.php

@@ -528,6 +528,26 @@ abstract class AbstractLayoutTest extends \Symfony\Component\Form\Test\FormInteg
         );
     }
 
+    public function testSelectWithSizeBiggerThanOneCanBeRequired()
+    {
+        $form = $this->factory->createNamed('name', 'choice', null, array(
+            'choices' => array('a', 'b'),
+            'choices_as_values' => true,
+            'multiple' => false,
+            'expanded' => false,
+            'attr' => array('size' => 2),
+        ));
+
+        $this->assertWidgetMatchesXpath($form->createView(), array(),
+'/select
+    [@name="name"]
+    [@required="required"]
+    [@size="2"]
+    [count(./option)=2]
+'
+        );
+    }
+
     public function testSingleChoiceWithoutTranslation()
     {
         $form = $this->factory->createNamed('name', 'choice', '&a', array(
@@ -1001,6 +1021,7 @@ abstract class AbstractLayoutTest extends \Symfony\Component\Form\Test\FormInteg
             'multiple' => false,
             'expanded' => true,
             'placeholder' => 'Test&Me',
+            'required' => false,
         ));
 
         $this->assertWidgetMatchesXpath($form->createView(), array(),

src/Symfony/Component/Form/Tests/Extension/Core/Type/ChoiceTypeTest.php

@@ -1689,7 +1689,7 @@ class ChoiceTypeTest extends \Symfony\Component\Form\Test\TypeTestCase
             'expanded' => $expanded,
             'required' => $required,
             'placeholder' => $placeholder,
-            'choices' => array('A' => 'a', 'Empty' => ''),
+            'choices' => array('Empty' => '', 'A' => 'a'),
             'choices_as_values' => true,
         ));
         $view = $form->createView();
@@ -1716,9 +1716,9 @@ class ChoiceTypeTest extends \Symfony\Component\Form\Test\TypeTestCase
             array(false, true, false, '', 'None'),
             array(false, true, false, null, null),
             array(false, true, false, false, null),
-            array(false, true, true, 'foobar', 'foobar'),
+            // required radios should never have a placeholder
-            // radios should never have an empty label
+            array(false, true, true, 'foobar', null),
-            array(false, true, true, '', 'None'),
+            array(false, true, true, '', null),
             array(false, true, true, null, null),
             array(false, true, true, false, null),
             // multiple non-expanded