Description:
------------
When "returning" a string from a file, the result behaves differently if used in a condition containing the  || operator

setup an "environment.php" file that contains:

<?php 
return "production";

then run the script attached:

Test script:
---------------
<?php

// determine application environment
$environmentFile = 'environment.php';
if (!file_exists($environmentFile)) {
    $environment = 'development';
} elseif ($environment = include $environmentFile) {
    // do nothing
} else {
    $environment = 'development';
}

echo $environment . " ";

if (!file_exists($environmentFile) || ($environment = include $environmentFile)) {
    $environment = 'development';
}

echo $environment;

Expected result:
----------------
the script should echo the string
"production production"

Actual result:
--------------
"production development"