[Process] moved env check to the Process class (refs #8227)

Process.php

@@ -145,10 +145,7 @@ public function __construct($commandline, $cwd = null, array $env = null, $stdin
             $this->cwd = getcwd();
         }
         if (null !== $env) {
-            $this->env = array();
-            foreach ($env as $key => $value) {
-                $this->env[(binary) $key] = (binary) $value;
-            }
+            $this->setEnv($env);
         } else {
             $this->env = null;
         }
@@ -890,13 +887,25 @@ public function getEnv()
     /**
      * Sets the environment variables.
      *
+     * An environment variable value should be a string.
+     * If it is an array, the variable is ignored.
+     *
+     * That happens in PHP when 'argv' is registered into
+     * the $_ENV array for instance.
+     *
      * @param array $env The new environment variables
      *
      * @return self The current Process instance
      */
     public function setEnv(array $env)
     {
-        $this->env = $env;
+        // Process can not handle env values that are arrays
+        $env = array_filter($env, function ($value) { if (!is_array($value)) { return true; } });
+
+        $this->env = array();
+        foreach ($env as $key => $value) {
+            $this->env[(binary) $key] = (binary) $value;
+        }
 
         return $this;
     }

ProcessBuilder.php

@@ -151,9 +151,6 @@ public function getProcess()
             $env = $this->env;
         }
 
-        // Process can not handle env values that are arrays
-        $env = $env ? array_filter($env, function ($value) { if (!is_array($value)) { return true; } }) : $env;
-
         return new Process($script, $this->cwd, $env, $this->stdin, $this->timeout, $options);
     }
 }