Issue #3413632: When Converting an Image's Format with Image Styles, Replace...

Issue #3413632: When Converting an Image's Format with Image Styles, Replace the Extension instead of Appending

Closes #3413632

core/modules/image/src/Entity/ImageStyle.php

@@ -516,6 +516,8 @@ protected function addExtension($path) {
     $original_extension = pathinfo($path, PATHINFO_EXTENSION);
     $extension = $this->getDerivativeExtension($original_extension);
     if ($original_extension !== $extension) {
+      $directory_path = pathinfo($path, PATHINFO_DIRNAME);
+      $path = $directory_path . pathinfo($path, PATHINFO_FILENAME);
       $path .= '.' . $extension;
     }
     return $path;