Dont force portrait orientation during merge if not specified (#29)

* Dont force portrait orientation during merge if not specified

* Support for php 5.5.9

Co-authored-by: Jason Toh <[email protected]>

Author: Jason-Toh

src/PDFMerger/PDFMerger.php

@@ -195,7 +195,7 @@ public function addPDF($filePath, $pages = 'all', $orientation = null) {
      *
      * @throws \Exception if there are now PDFs to merge
      */
-    public function merge($orientation = 'P') {
+    public function merge($orientation = null) {
         $this->doMerge($orientation, false);
     }
 
@@ -228,18 +228,20 @@ protected function doMerge($orientation, $duplexSafe) {
                 for ($i = 1; $i <= $count; $i++) {
                     $template   = $oFPDI->importPage($i);
                     $size       = $oFPDI->getTemplateSize($template);
+                    $autoOrientation = isset($file['orientation']) ? $file['orientation'] : $size['orientation'];
 
-                    $oFPDI->AddPage($file['orientation'], [$size['width'], $size['height']]);
+                    $oFPDI->AddPage($autoOrientation, [$size['width'], $size['height']]);
                     $oFPDI->useTemplate($template);
                 }
             } else {
                 foreach ($file['pages'] as $page) {
                     if (!$template = $oFPDI->importPage($page)) {
-                        throw new \Exception("Could not load page '$page' in PDF '".$file['name']."'. Check that the page exists.");
+                        throw new \Exception("Could not load page '$page' in PDF '" . $file['name'] . "'. Check that the page exists.");
                     }
                     $size = $oFPDI->getTemplateSize($template);
+                    $autoOrientation = isset($file['orientation']) ? $file['orientation'] : $size['orientation'];
 
-                    $oFPDI->AddPage($file['orientation'], [$size['width'], $size['height']]);
+                    $oFPDI->AddPage($autoOrientation, [$size['width'], $size['height']]);
                     $oFPDI->useTemplate($template);
                 }
             }