From 0ab17d2158845681f58b5fc35beeeecf64a5cc85 Mon Sep 17 00:00:00 2001
From: Mike Schroder <mikeschroder@git.wordpress.org>
Date: Fri, 18 Nov 2016 22:21:19 +0000
Subject: [PATCH] Media: Allow override of PDF setup for multiple pages or DPI.

After [39187], WordPress started loading only the first page of a PDF.

This is appropriate for performance, but made it impossible to
write plugins that read other pages without overriding `load()`.

Introduces `WP_Image_Editor_Imagick->pdf_setup()`, to allow an override
to change WordPress' rendering DPI defaults or which pages are loaded.

Fixes #38832. See #38522, #31050.
Props markoheijnen, joemcgill, mikeschroder.

git-svn-id: https://develop.svn.wordpress.org/trunk@39303 602fd350-edb4-49c9-b593-d223f7449a82
---
 .../class-wp-image-editor-imagick.php         | 30 +++++++++++++++----
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/src/wp-includes/class-wp-image-editor-imagick.php b/src/wp-includes/class-wp-image-editor-imagick.php
index c89706cd58..fc6fc933ae 100644
--- a/src/wp-includes/class-wp-image-editor-imagick.php
+++ b/src/wp-includes/class-wp-image-editor-imagick.php
@@ -149,13 +149,8 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 			$file_parts = pathinfo( $this->file );
 			$filename = $this->file;
 
-			// By default, PDFs are rendered in a very low resolution.
-			// We want the thumbnail to be readable, so increase the rendering dpi.
 			if ( 'pdf' == strtolower( $file_parts['extension'] ) ) {
-				$this->image->setResolution( 128, 128 );
-
-				// Only load the first page.
-				$filename .= '[0]';
+				$filename = $this->pdf_setup();
 			}
 
 			// Reading image after Imagick instantiation because `setResolution`
@@ -743,4 +738,27 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 		return true;
 	}
 
+	/**
+	 * Sets up Imagick for PDF processing.
+	 * Increases rendering DPI and only loads first page.
+	 *
+	 * @since 4.7.0
+	 * @access protected
+	 *
+	 * @return string|WP_Error File to load or WP_Error on failure.
+	 */
+	protected function pdf_setup() {
+		try {
+			// By default, PDFs are rendered in a very low resolution.
+			// We want the thumbnail to be readable, so increase the rendering DPI.
+			$this->image->setResolution( 128, 128 );
+
+			// Only load the first page.
+			return $this->file . '[0]';
+		}
+		catch ( Exception $e ) {
+			return new WP_Error( 'pdf_setup_failed', $e->getMessage(), $this->file );
+		}
+	}
+
 }