TYPO3.Flow / propertyMapper, bug?

************SOLVED************
I need to configurate the mapping. You do that by a initializeCreateAction(), as it follows.
(I had a couple of annoying misprints such that it looked as it was not working)

/**
     * Adds the given new array of father objects to the father repository
     *
     *
     * @return void
     */
           public function initializeCreateAction() {

        $this->arguments['newFathers']->getPropertyMappingConfiguration()->forProperty('sons.*')->allowAllProperties()->setTypeConverterOption(
                'TYPO3\Flow\Property\TypeConverter\PersistentObjectConverter',
                \TYPO3\Flow\Property\TypeConverter\PersistentObjectConverter::CONFIGURATION_CREATION_ALLOWED,
                TRUE
        );
}


--------------------------------------------
MODEL father and son

FATHER
<?php
namespace Mario\Basic\Domain\Model;

/*                                                                        *
 * This script belongs to the Flow package "Mario.Basic".                 *
 *                                                                        *
 *                                                                        */
use Doctrine\ORM\Mapping as ORM;
use TYPO3\Flow\Annotations as Flow;

/**
 * A Father
 *
 * @Flow\Entity
 */
class Father {

        /**
     * @var string
     * @Flow\Validate(type="Text")
         * @Flow\Validate(type="NotEmpty")
     * @Flow\Validate(type="StringLength", options={ "minimum"=3, "maximum"=80 })
     * @Flow\Identity
     * @ORM\Column(length=80)
     */
    protected $name;

    /**
     * The sons
     * @var \Doctrine\Common\Collections\Collection<\Mario\Basic\Domain\Model\Son>
     * @ORM\OneToMany(mappedBy="father", cascade={"persist"}, orphanRemoval=true)
     */
    protected $sons;


    /**
     * Get the Father's name
     *
     * @return string The Father's name
     */
    public function getName() {
        return $this->name;
    }

    /**
     * Sets this Father's name
     *
     * @param string $name The Father's name
     * @return void
     */
    public function setName($name) {
        $this->name = $name;
    }

        /**
     * Adds a son to this father
     *
     * @param \Mario\Basic\Domain\Model\Son $son
     * @return void
     */
    public function addSons(\Mario\Basic\Domain\Model\Son $son) {
        $son->setFather($this);
        $this->sons->add($son);
    }


    /**
     * Removes a son from this father
     *
     * @param \Mario\Basic\Domain\Model\Son $son
     * @return void
     */
    public function removeSons(\Mario\Basic\Domain\Model\Son $son) {
        $this->sons->removeElement($son);
    }

    /**
     * Get the Father's sons
     *
     * @return \Doctrine\Common\Collections\Collection The Father's sons
     */
    public function getSons() {
        return $this->sons;
    }

    /**
     * Sets this Father's sons
     *
     * @param \Doctrine\Common\Collections\Collection $sons The Father's sons
     * @return void
     */
    public function setSons(\Doctrine\Common\Collections\Collection $sons) {
/* NOTE next line to assign a father to each son, when you create a father and his sons from the same new template. */
                 foreach ($sons as $son){$son->setFather($this);}
         $this->sons = $sons;
    }
}

SON

<?php
namespace Mario\Basic\Domain\Model;

/*                                                                        *
 * This script belongs to the Flow package "Mario.Basic".                 *
 *                                                                        *
 *                                                                        */

use TYPO3\Flow\Annotations as Flow;
use Doctrine\ORM\Mapping as ORM;

/**
 * A Son
 *
 * @Flow\Entity
 */
class Son {

    /**
     * The father
     * @var \Mario\Basic\Domain\Model\Father
     * @ORM\ManyToOne(inversedBy="sons")
     */
    protected $father;

    /**
     * @var string
     * @Flow\Validate(type="Text")
         * @Flow\Validate(type="NotEmpty")
     * @Flow\Validate(type="StringLength", options={ "minimum"=3, "maximum"=80 })
     * @Flow\Identity
     * @ORM\Column(length=80)
     */
    protected $nameson;

    /**
     * Get the Son's father
     *
     * @return \Mario\Basic\Domain\Model\Father The Son's father
     */
    public function getFather() {
        return $this->father;
    }

    /**
     * Sets this Son's father
     *
     * @param \Mario\Basic\Domain\Model\Father $father The Son's father
     * @return void
     */
    public function setFather(\Mario\Basic\Domain\Model\Father $father) {
        $this->father = $father;
    }

    /**
     * Get the Son's nameson
     *
     * @return string The Son's nameson
     */
    public function getNameson() {
        return $this->nameson;
    }

    /**
     * Sets this Son's nameson
     *
     * @param string $name The Son's nameson
     * @return void
     */
    public function setNameson($nameson) {
        $this->nameson = $nameson;
    }
}
?>

FATHER CONTROLLER index, new, create and show

<?php
namespace Mario\Basic\Controller;

/*                                                                        *
 * This script belongs to the Flow package "Mario.Basic".                 *
 *                                                                        *
 *                                                                        */

use \TYPO3\Flow\Persistence\QueryInterface;
use \TYPO3\Fluid\View\TemplateView;
use TYPO3\Flow\Annotations as Flow;

/**
 * Father controller for the Mario.Basic package
 *
 * @Flow\Scope("singleton")
 */
class FatherController extends \TYPO3\Flow\Mvc\Controller\ActionController {

    /**
     * @Flow\Inject
     * @var \Mario\Basic\Domain\Repository\FatherRepository
     */
    protected $fatherRepository;

        /**
     * @Flow\Inject
     * @var \Mario\Basic\Domain\Repository\SonRepository
     */
    protected $sonRepository;

        /**
     * @var \Mario\Basic\Domain\Model\Father
     */
    protected $father;

    /**
     * Shows a list of fathers
     *
     * @return void
     */
    public function indexAction() {
        $this->view->assign('fathers', $this->fatherRepository->findAll());
    }

    /**
     * Shows a single father object
     *
     * @param \Mario\Basic\Domain\Model\Father $father The father to show
     * @return void
     */
    public function showAction(\Mario\Basic\Domain\Model\Father $father) {
        $this->view->assign('father', $father);
    }

    /**
     * Shows a form for creating a new father object
     *
     * @return void
     */
    public function newAction() {
    }

    /**
     * Adds the given new array of father objects to the father repository
     *
     * @param \Doctrine\Common\Collections\Collection<\Mario\Basic\Domain\Model\Father> $newFathers A collection of new fathers to add
     * @return void
     */
    public function createAction(\Doctrine\Common\Collections\Collection $newFathers) {

        foreach($newFathers as $father){
        $this->fatherRepository->add($father);  }

                $this->addFlashMessage('Created a new father and his sons');
        $this->redirect('index');
    }
}

?>

TEMPLATE NEW. HTML FORM, case two fathers, a son each

<form name="newFathers" action="mario.basic/father/create" method="post">
<div style="display: none">
<input name="__referrer[@package]" value="Mario.Basic" type="hidden">
<input name="__referrer[@subpackage]" value="" type="hidden">
<input name="__referrer[@controller]" value="Father" type="hidden">
<input name="__referrer[@action]" value="new" type="hidden">
<input name="__referrer[arguments]" value="....." type="hidden">
<input name="__trustedProperties" value=".....">

<label for="name">Name</label>
<input name="newFathers[0][name]" type="text">
<label for="nameson">Name Son</label><br>
<input id="sonInput00" name="newFathers[0][sons][0][nameson]" type="text">
<label for="name">Name</label>
<input name="newFathers[1][name]" type="text">
<label for="nameson">Name Son</label>
<input id="sonInput10" name="newFathers[1][sons][0][nameson]" type="text">
<input name="" value="Create" type="submit">
</form>

note POST array:
newFathers[0][name]
newFathers[0][sons][0][nameson]
newFathers[1][name]
newFathers[1][sons][0][nameson]

The above case goes thru fine, both fathers are created, both sons too, every db field is filled in correctly.

If I try the same with two fathers, a son for the former and TWO sons for the latter

<form name="newFathers" action="mario.basic/father/create" method="post">
<div style="display: none">
<input name="__referrer[@package]" value="Mario.Basic" type="hidden">
<input name="__referrer[@subpackage]" value="" type="hidden">
<input name="__referrer[@controller]" value="Father" type="hidden">
<input name="__referrer[@action]" value="new" type="hidden">
<input name="__referrer[arguments]" value="....." type="hidden">
<input name="__trustedProperties" value="....">

<label for="name">Name</label>
<input name="newFathers[0][name]" type="text">
<label for="nameson">Name Son</label><br>
<input id="sonInput00" name="newFathers[0][sons][0][nameson]" type="text">
<label for="name">Name</label>
<input name="newFathers[1][name]" type="text">
<label for="nameson">Name Son</label><br>
<input id="sonInput10" name="newFathers[1][sons][0][nameson]" type="text">
<input id="sonInput11" name="newFathers[1][sons][1][nameson]" type="text">
<input name="" value="Create" type="submit">
</form>

note POST array:
newFathers[0][name]
newFathers[0][sons][0][nameson]
newFathers[1][name]
newFathers[1][sons][0][nameson]
newFathers[1][sons][1][nameson]    <<<<-----

then I get error,
#1297759968: Exception while property mapping for target type "Doctrine\Common\Collections\Collection<\Mario\Basic\Domain\Model\Father>", at property path "1.sons": It is not allowed to map property "1".

I understand error is thrown in by propertyMapper::convert(), indeed by  propertyMapper::doMapping().

If I just - brutally - modify doMapping as it follows, objects (both father, all three sons) are created fine.

doMapping() ad hoc MODIFIED

<?php

protected function doMapping($source, $targetType, \TYPO3\Flow\Property\PropertyMappingConfigurationInterface $configuration, &$currentPropertyPath) {
        if (is_object($source)) {
            $targetType = $this->parseCompositeType($targetType);
            if ($source instanceof $targetType) {
                return $source;
            }
        }

        if ($source === NULL) {
            $source = '';
        }

        $typeConverter = $this->findTypeConverter($source, $targetType, $configuration);
        $targetType = $typeConverter->getTargetTypeForSource($source, $targetType, $configuration);

        if (!is_object($typeConverter) || !($typeConverter instanceof \TYPO3\Flow\Property\TypeConverterInterface)) {
            throw new Exception\TypeConverterException('Type converter for "' . $source . '" -> "' . $targetType . '" not found.');
        }

        $convertedChildProperties = array();
        foreach ($typeConverter->getSourceChildPropertiesToBeConverted($source) as $sourcePropertyName => $sourcePropertyValue) {
            $targetPropertyName = $configuration->getTargetPropertyName($sourcePropertyName);


///// ADD the following  configuration settings
$configuration->setTypeConverterOptions('TYPO3\Flow\Property\TypeConverter\PersistentObjectConverter', array(
            \TYPO3\Flow\Property\TypeConverter\PersistentObjectConverter::CONFIGURATION_CREATION_ALLOWED => TRUE,
            \TYPO3\Flow\Property\TypeConverter\PersistentObjectConverter::CONFIGURATION_MODIFICATION_ALLOWED => TRUE
        ));


/////// COMMENT OUT the following lines
/*
if ($configuration->shouldSkip($targetPropertyName)) {
                continue;
            }
//print_r($configuration);
//print_r($configuration->getConfigurationFor($targetPropertyName));
            if (!$configuration->shouldMap($targetPropertyName)) {
                if ($configuration->shouldSkipUnknownProperties()) {
                    continue;
                }
                throw new Exception\InvalidPropertyMappingConfigurationException('It is not allowed to map property "' . $targetPropertyName . '". You need to use $propertyMappingConfiguration->allowProperties(\'' . $targetPropertyName . '\') to enable mapping of this property.', 1335969887);
            }
*/

            $targetPropertyType = $typeConverter->getTypeOfChildProperty($targetType, $targetPropertyName, $configuration);

            $subConfiguration = $configuration->getConfigurationFor($targetPropertyName);

            $currentPropertyPath[] = $targetPropertyName;

            $targetPropertyValue = $this->doMapping($sourcePropertyValue, $targetPropertyType, $subConfiguration, $currentPropertyPath);
            array_pop($currentPropertyPath);
            if (!($targetPropertyValue instanceof \TYPO3\Flow\Error\Error)) {
                $convertedChildProperties[$targetPropertyName] = $targetPropertyValue;
            }
        }
        $result = $typeConverter->convertFrom($source, $targetType, $convertedChildProperties, $configuration);

        if ($result instanceof \TYPO3\Flow\Error\Error) {
            $this->messages->forProperty(implode('.', $currentPropertyPath))->addError($result);
        }
        return $result;
    }
?>


QUESTIONS ARE:
-- should not be possible to create more fathers, each with many of his sons, at once? How to fix as that is possible without special configurations_
-- isn't it somehow mis-programmed that the first case above goes thru and the second fails? and why so?

thks