From c5c9e424243c4c5775e73a616dbf6d605a5f50d8 Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Thu, 24 Aug 2017 16:59:53 +0200
Subject: [PATCH] Suppress warnings for corrupt PNG, throw an exception instead

---
 .../image/adapter/GDImageAdapter.class.php    |  6 ++++-
 .../worker/UserRebuildDataWorker.class.php    | 23 +++++++++++++++++--
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php b/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
index c8689c9e15..a768e0ce74 100644
--- a/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
+++ b/wcfsetup/install/files/lib/system/image/adapter/GDImageAdapter.class.php
@@ -95,7 +95,11 @@ class GDImageAdapter implements IImageAdapter {
 			break;
 			
 			case IMAGETYPE_PNG:
-				$this->image = imagecreatefrompng($file);
+				// suppress warnings and properly handle errors
+				$this->image = @imagecreatefrompng($file);
+				if ($this->image === false) {
+					throw new SystemException("Could not read png image '".$file."'.");
+				}
 			break;
 			
 			default:
diff --git a/wcfsetup/install/files/lib/system/worker/UserRebuildDataWorker.class.php b/wcfsetup/install/files/lib/system/worker/UserRebuildDataWorker.class.php
index 8e32048816..7ecb4c3da5 100644
--- a/wcfsetup/install/files/lib/system/worker/UserRebuildDataWorker.class.php
+++ b/wcfsetup/install/files/lib/system/worker/UserRebuildDataWorker.class.php
@@ -9,6 +9,7 @@ use wcf\data\user\UserEditor;
 use wcf\data\user\UserList;
 use wcf\data\user\UserProfileAction;
 use wcf\system\database\util\PreparedStatementConditionBuilder;
+use wcf\system\exception\SystemException;
 use wcf\system\html\input\HtmlInputProcessor;
 use wcf\system\image\ImageHandler;
 use wcf\system\user\activity\point\UserActivityPointHandler;
@@ -160,7 +161,16 @@ class UserRebuildDataWorker extends AbstractRebuildDataWorker {
 					// make avatar quadratic
 					$width = $height = min($width, $height, UserAvatar::AVATAR_SIZE);
 					$adapter = ImageHandler::getInstance()->getAdapter();
-					$adapter->loadFile($avatar->getLocation());
+					
+					try {
+						$adapter->loadFile($avatar->getLocation());
+					}
+					catch (SystemException $e) {
+						// broken image
+						$editor->delete();
+						continue;
+					}
+					
 					$thumbnail = $adapter->createThumbnail($width, $height, false);
 					$adapter->writeImage($thumbnail, $avatar->getLocation());
 				}
@@ -168,7 +178,16 @@ class UserRebuildDataWorker extends AbstractRebuildDataWorker {
 				if ($width != UserAvatar::AVATAR_SIZE || $height != UserAvatar::AVATAR_SIZE) {
 					// resize avatar
 					$adapter = ImageHandler::getInstance()->getAdapter();
-					$adapter->loadFile($avatar->getLocation());
+					
+					try {
+						$adapter->loadFile($avatar->getLocation());
+					}
+					catch (SystemException $e) {
+						// broken image
+						$editor->delete();
+						continue;
+					}
+					
 					$adapter->resize(0, 0, $width, $height, UserAvatar::AVATAR_SIZE, UserAvatar::AVATAR_SIZE);
 					$adapter->writeImage($adapter->getImage(), $avatar->getLocation());
 					$width = $height = UserAvatar::AVATAR_SIZE;
-- 
2.20.1