feature #42387 [Form] Deprecate calling FormErrorIterator::children() if the current element is not iterable (W0rma)

This PR was merged into the 5.4 branch.

Discussion
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[Form] Deprecate calling FormErrorIterator::children() if the current element is not iterable

| Q             | A
| ------------- | ---
| Branch?       | 5.4 for features
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | yes
| Tickets       | symfony/symfony#42301 (comment)
| License       | MIT
| Doc PR        |

Commits
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d8e74fc8df * Deprecated calling `FormErrorIterator::children()` if the current element is not iterable

Author: fabpot

CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 5.4
 ---
 
+ * Deprecate calling `FormErrorIterator::children()` if the current element is not iterable.
  * Allow to pass `TranslatableMessage` objects to the `help` option
 
 5.3

FormErrorIterator.php

@@ -13,6 +13,7 @@
 
 use Symfony\Component\Form\Exception\BadMethodCallException;
 use Symfony\Component\Form\Exception\InvalidArgumentException;
+use Symfony\Component\Form\Exception\LogicException;
 use Symfony\Component\Form\Exception\OutOfBoundsException;
 use Symfony\Component\Validator\ConstraintViolation;
 
@@ -213,13 +214,16 @@ public function hasChildren()
     }
 
     /**
-     * Alias of {@link current()}.
-     *
      * @return self
      */
     #[\ReturnTypeWillChange]
     public function getChildren()
     {
+        if (!$this->hasChildren()) {
+            trigger_deprecation('symfony/form', '5.4', 'Calling "%s()" if the current element is not iterable is deprecated, call "%s" to get the current element.', __METHOD__, self::class.'::current()');
+            // throw new LogicException(sprintf('The current element is not iterable. Use "%s" to get the current element.', self::class.'::current()'));
+        }
+
         return current($this->errors);
     }