Make boolean fields not required by default.

Having boolean fields (checkboxes) marked as required by default makes
working with optional checkboxes really hard. Instead we won't
automatically mark checkboxes as required.

Refs #5158

src/View/Form/EntityContext.php

@@ -331,8 +331,10 @@ public function isRequired($field) {
 		if (!$validator->hasField($field)) {
 			return false;
 		}
-		$allowed = $validator->isEmptyAllowed($field, $isNew);
-		return $allowed === false;
+		if ($this->type($field) !== 'boolean') {
+			return $validator->isEmptyAllowed($field, $isNew) === false;
+		}
+		return false;
 	}
 
 /**

tests/TestCase/View/Form/EntityContextTest.php

@@ -592,6 +592,32 @@ public function testValAssociatedCustomIds() {
 		$this->assertEquals([1, 4], $result);
 	}
 
+/**
+ * Test validator for boolean fields.
+ *
+ * @return void
+ */
+	public function testIsRequiredBooleanField() {
+		$this->_setupTables();
+
+		$context = new EntityContext($this->request, [
+			'entity' => new Entity(),
+			'table' => 'Articles',
+		]);
+		$articles = TableRegistry::get('Articles');
+		$articles->schema()->addColumn('comments_on', [
+			'type' => 'boolean'
+		]);
+
+		$validator = $articles->validator();
+		$validator->add('comments_on', 'is_bool', [
+			'rule' => 'boolean'
+		]);
+		$articles->validator('default', $validator);
+
+		$this->assertFalse($context->isRequired('title'));
+	}
+
 /**
  * Test validator as a string.
  *