[BUG] Updating a model fails after fetching its related records

[zsilbi]

When fetching a record (Robots) and getting it's related models (RobotParts) a RuntimeException is being thrown when trying to save/update afterwards.

My observations:

• It only happens when after accessing hasMany or hasManyToMany type of relations.
• I have tried a lot of different models (names, aliases) and relations
• When creating a new model the error not occurs
• It doesn't matter if there are any related records in RobotParts table
• It only occurs when accessing the related records as property (saving after $robot->getRobotParts() works fine)

Output error when using hasMany

RuntimeException
Call to undefined method \x01::writeattribute() 

Output error when using hasManyToMany

RuntimeException
Call to undefined method \x01::save() 

Script to reproduce the issue (only the relevant parts)

class Robots extends \Phalcon\Mvc\Model {
    public function initialize() {
        $this->hasMany('id', 'RobotParts', 'robotId', [
            'alias' => 'robotParts'
        ]);
    }
}

public function main() {
    $robot = Robots::findFirst();
    $robot->robotParts;
    $robot->save(); // or $robot->update();
}

Current workaround:

public function main() {
    $robot = Robots::findFirst();
    $robot->getRobotParts();
    $robot->save();
}

It's a widely used feature and it's very easy to reproduce so I think - and hope - that it must be some kind of incompability, otherwise it would have been discovered previously.

Details

• Phalcon version: 4.0.0-alpha.3
• PHP Version: 7.2.16-1
• Operating System: Ubuntu 16.04
• Installation type: Compiling from source
• Zephir version (if any): Version 0.11.11-b661a58
• Server: nginx
• Other related info (Database, table schema): MariaDB 10.1.37

[zsilbi]

I wrote tests to confirm the issue and it failed in CI with a rather strange error message.

[PHPUnit\Framework\Exception] Invalid callback , no array or string given

[niden]

Resolved

[niden]

Actually my bad, this was not resolved 100%. We need to do a lot more regression testing with the proposed fix from the PR attached to this issue.

[niden]

Resolved in #14035