Media: Prevent unnecessary whitespace around PDF Thumbnails.

Stops unintended whitespace from showing around PDF thumbnails
when the PDF creation tool utilized a CropBox.

Props michelweimerskirch, joemcgill.
Fixes #45598.
Built from https://develop.svn.wordpress.org/trunk@46238


git-svn-id: http://core.svn.wordpress.org/trunk@46050 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-image-editor-imagick.php

@@ -787,6 +787,10 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 			// We want the thumbnail to be readable, so increase the rendering DPI.
 			$this->image->setResolution( 128, 128 );
 
+			// When generating thumbnails from cropped PDF pages, Imagemagick uses the uncropped
+			// area (resulting in unnecessary whitespace) unless the following option is set.
+			$this->image->setOption( 'pdf:use-cropbox', true );
+
 			// Only load the first page.
 			return $this->file . '[0]';
 		} catch ( Exception $e ) {

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-46237';
+$wp_version = '5.3-alpha-46238';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.