ENGCOM-2956: [Forwardport] Fixes black background for png images in wysiwyg editors. #17857

Author: ishakhsuvarov

lib/internal/Magento/Framework/Image/Adapter/Gd2.php

@@ -5,6 +5,9 @@
  */
 namespace Magento\Framework\Image\Adapter;
 
+/**
+ * @SuppressWarnings(PHPMD.ExcessiveClassComplexity)
+ */
 class Gd2 extends \Magento\Framework\Image\Adapter\AbstractAdapter
 {
     /**
@@ -66,6 +69,16 @@ public function open($filename)
             $this->_getCallback('create', null, sprintf('Unsupported image format. File: %s', $this->_fileName)),
             $this->_fileName
         );
+        $fileType = $this->getImageType();
+        if (in_array($fileType, [IMAGETYPE_PNG, IMAGETYPE_GIF])) {
+            $this->_keepTransparency = true;
+            if ($this->_imageHandler) {
+                $isAlpha = $this->checkAlpha($this->_fileName);
+                if ($isAlpha) {
+                    $this->_fillBackgroundColor($this->_imageHandler);
+                }
+            }
+        }
     }
 
     /**