images created with Symfony and Twig sometimes display wrong - image

Question

I have some images created with Symfony, they are generated as:
src="data:image;base64,/9j/4AAQSkZJRg... etc"
data-holder-rendered="true"
With this code in my controller:
$sql = "select id,nombre,descripcion,encode(imagen, 'base64') as imagen from data.servicios_mapa order by destacado DESC, fecha_creacion DESC LIMIT 4" ;
$stmt = $conn->prepare( $sql );
$stmt->execute();
$mapas = $stmt->fetchAll();
$datos_mapa = array();
foreach($mapas as $m){
if($m['imagen'] != '' || $m['imagen'] != null){
$m['imagen'] = "data:image;base64,".$m['imagen'];
}else{
$m['imagen'] = "/imgs/no-image.jpg";
}
$datos_mapa[] = $m;
}
return $this->render('FrontendBundle:Default:index.html.twig', array("estructura"=>json_encode(array()),"datosmapas"=>$datos_mapa) );
Then in Twig:
<img src="{{ mapa.imagen }}" class="img-responsive fix-height">
But some of them are wrongly diplayed, like the left one:
http://fotos.subefotos.com/5909f04a9cfa9be2c4b286d1b87727eco.png
What could be the reasson? they are all generated with the same code.

Answer 1

Inside your loop, the else for the condition if($m['imagen'] != '' || $m['imagen'] != null) is never reached when $m['imagen'] == null or $m['imagen'] == ''
because null != '' gives true, and '' != null gives true
So you will have <img src="data:image;base64," class="img-responsive fix-height">
You should change it to : if($m['imagen'] != '' && $m['imagen'] != null)