From a8fd670237e4983b08a2f92d492946d570d8238b Mon Sep 17 00:00:00 2001
From: Anthony Burchell <antpb@git.wordpress.org>
Date: Wed, 15 Feb 2023 21:30:20 +0000
Subject: [PATCH] Media: Add `setImagickTimeLimit()` function to avoid timeout
 in Imagick operations.

Previously, Imagick operations could silently error by timeout and produce unexpected results. The new `setImagickTimeLimit()` function will better handle garbage collection in these cases as well as better align Imagick's timeout with PHP timeout, assuming it is set.

Props drzraf, audrasjb, costdev.
Fixes #52569.


git-svn-id: https://develop.svn.wordpress.org/branches/6.1@55348 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/includes/class-wp-debug-data.php |  2 +
 .../class-wp-image-editor-imagick.php         | 46 +++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/src/wp-admin/includes/class-wp-debug-data.php b/src/wp-admin/includes/class-wp-debug-data.php
index 67d79b9369..d8b06f18a8 100644
--- a/src/wp-admin/includes/class-wp-debug-data.php
+++ b/src/wp-admin/includes/class-wp-debug-data.php
@@ -580,6 +580,7 @@ class WP_Debug_Data {
 				'map'    => ( defined( 'imagick::RESOURCETYPE_MAP' ) ? size_format( $imagick->getResourceLimit( imagick::RESOURCETYPE_MAP ) ) : $not_available ),
 				'memory' => ( defined( 'imagick::RESOURCETYPE_MEMORY' ) ? size_format( $imagick->getResourceLimit( imagick::RESOURCETYPE_MEMORY ) ) : $not_available ),
 				'thread' => ( defined( 'imagick::RESOURCETYPE_THREAD' ) ? $imagick->getResourceLimit( imagick::RESOURCETYPE_THREAD ) : $not_available ),
+				'time'   => ( defined( 'imagick::RESOURCETYPE_TIME' ) ? $imagick->getResourceLimit( imagick::RESOURCETYPE_TIME ) : $not_available ),
 			);
 
 			$limits_debug = array(
@@ -589,6 +590,7 @@ class WP_Debug_Data {
 				'imagick::RESOURCETYPE_MAP'    => ( defined( 'imagick::RESOURCETYPE_MAP' ) ? size_format( $imagick->getResourceLimit( imagick::RESOURCETYPE_MAP ) ) : 'not available' ),
 				'imagick::RESOURCETYPE_MEMORY' => ( defined( 'imagick::RESOURCETYPE_MEMORY' ) ? size_format( $imagick->getResourceLimit( imagick::RESOURCETYPE_MEMORY ) ) : 'not available' ),
 				'imagick::RESOURCETYPE_THREAD' => ( defined( 'imagick::RESOURCETYPE_THREAD' ) ? $imagick->getResourceLimit( imagick::RESOURCETYPE_THREAD ) : 'not available' ),
+				'imagick::RESOURCETYPE_TIME'   => ( defined( 'imagick::RESOURCETYPE_TIME' ) ? $imagick->getResourceLimit( imagick::RESOURCETYPE_TIME ) : 'not available' ),
 			);
 
 			$info['wp-media']['fields']['imagick_limits'] = array(
diff --git a/src/wp-includes/class-wp-image-editor-imagick.php b/src/wp-includes/class-wp-image-editor-imagick.php
index f413387233..71e4fb0392 100644
--- a/src/wp-includes/class-wp-image-editor-imagick.php
+++ b/src/wp-includes/class-wp-image-editor-imagick.php
@@ -253,6 +253,48 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 		return parent::update_size( $width, $height );
 	}
 
+	/**
+	 * Depending on configuration, Imagick processing may take time.
+	 *
+	 * Multiple problems exist if PHP timeouts before ImageMagick completed:
+	 * 1. Temporary files aren't cleaned by ImageMagick garbage collection.
+	 * 2. No clear error is provided.
+	 * 3. The cause of such timeout can be hard to pinpoint.
+	 *
+	 * This function, which is expected to be run before heavy image routines, resolves
+	 * point 1 above by aligning Imagick's timeout with PHP's timeout, assuming it's set.
+	 *
+	 * Note: Imagick resource exhaustion does not issue catchable exceptions (yet)
+	 *       See https://github.com/Imagick/imagick/issues/333
+	 * Note: The resource limit isn't saved/restored. It applies to
+	 *       subsequent image operations within the time of the HTTP request.
+	 *
+	 * @since 6.2.0
+	 *
+	 * @return int|null Whether the new limit or null if none was set
+	 */
+	public static function setImagickTimeLimit() {
+		if ( ! defined( 'Imagick::RESOURCETYPE_TIME' ) ) {
+			return null;
+		}
+
+		// Returns PHP_FLOAT_MAX if unset.
+		$imagick_timeout = Imagick::getResourceLimit( Imagick::RESOURCETYPE_TIME );
+
+		// Convert to an integer, keeping in mind that: 0 === (int) PHP_FLOAT_MAX.
+		$imagick_timeout = $imagick_timeout > PHP_INT_MAX ? PHP_INT_MAX : (int) $imagick_timeout;
+
+		$php_timeout = intval( ini_get( 'max_execution_time' ) );
+
+		if ( $php_timeout > 1 && $php_timeout < $imagick_timeout ) {
+			// $limit = $php_timeout - 1;
+			$limit = floatval( 0.8 * $php_timeout );
+			Imagick::setResourceLimit( Imagick::RESOURCETYPE_TIME, $limit );
+
+			return $limit;
+		}
+	}
+
 	/**
 	 * Resizes current image.
 	 *
@@ -279,6 +321,8 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 
 		list( $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h ) = $dims;
 
+		self::setImagickTimeLimit();
+
 		if ( $crop ) {
 			return $this->crop( $src_x, $src_y, $src_w, $src_h, $dst_w, $dst_h );
 		}
@@ -545,6 +589,8 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 			$src_h -= $src_y;
 		}
 
+		self::setImagickTimeLimit();
+
 		try {
 			$this->image->cropImage( $src_w, $src_h, $src_x, $src_y );
 			$this->image->setImagePage( $src_w, $src_h, 0, 0 );