Only change to a drive letter first, if it is an absolute path on Windows.

Author: angrybrad

src/Command.php

@@ -149,7 +149,11 @@ public function setCommand($command)
         if ($this->getIsWindows()) {
             // Make sure to switch to correct drive like "E:" first if we have a full path in command
             $chdrive = (isset($command[1]) && $command[1]===':') ? $command[0].': && ' : '';
-            $command = sprintf($chdrive.'cd %s && %s', escapeshellarg(dirname($command)), basename($command));
+
+            // Absolute path. If it's a relative path, let it slide.
+            if ($chdrive) {
+                $command = sprintf($chdrive.'cd %s && %s', escapeshellarg(dirname($command)), basename($command));
+            }
         }
         $this->_command = $command;
         return $this;