ZF-11941: Segmentation fault rendering Zend_Form after condition check

Issue Type:
Bug
Created:
2011-12-15T17:40:05.000+0000
Last Updated:
2011-12-15T19:29:51.000+0000
Status:
Resolved
Fix version(s):
    Reporter:
    Arron Woods (idealarron)
    Assignee:
    Matthew Weier O'Phinney (matthew)
    Tags:
    • Zend_Form
    Related issues:
    Attachments:

    Description

    In certain versions of PHP (tested in 5.3.8) and Zend_Framework (tested in 1.11.11), when performing a conditional check on echoing a form instance from Zend_View, it causes PHP to crash.

    
<?php

require('Zend/Loader/Autoloader.php');
Zend_Loader_Autoloader::getInstance();

$view = new Zend_View();
$form = new Zend_Form;
$form->setView($view);

$input = new Zend_Form_Element_Text('input');
$input->setLabel('Input')
      ->setRequired();
$form->addElement($input);


$view->form = $form;
echo ($view->form)? $view->form : 'nothing';

    If I change the last line to the following, it works without failing:

    
echo ($view->form)? (string) $view->form : 'nothing';

    The segmentation fault occurs after the form has rendered in the shutdown phase of PHP.

    Any ideas why? I can work around it as described, but it took me a while to track this down!

    Comments

    Posted by Matthew Weier O'Phinney (matthew) on 2011-12-15T18:15:49.000+0000

    Honestly, I'd do this differently, and not use a ternary:

    
if (isset($view->form)) {
    echo $view->form;
} else {
    echo 'nothing';
}

    Since you're not in a view script, I'd actually go a little bit more explicit, and do the following to render the form:

    
echo $form->render($view);

    Either way, the "workarounds" are actually the appropriate solutions.

    Posted by Arron Woods (idealarron) on 2011-12-15T19:29:51.000+0000

    The code submitted is a test version, quite dissimilar to the application, which has the ternary in a view script.

    I concur and am happy to code it the verbose way, but for my own sanity, any idea why this would cause the segmentation fault?

    I ran it with gdb but the backtrace meant almost nothing to me, looked like php was trying to unregister resources at shutdown though.