From c38a5f3c0dfe2f6b6e6d51691a7b458f93f4212f Mon Sep 17 00:00:00 2001
From: Jeroen Hoekx <jeroen@hoekx.be>
Date: Sat, 12 Jun 2021 11:16:27 +0200
Subject: [PATCH] Test if thumbnail is GdImage

In PHP 8, GD returns GdImage objects and not resources. To check if a
thumbnail could be created, `is_resource()` was used. Since the
thumbnail is no longer a resource, this check now fails and the default
thumbnail was used for all maps.

See https://php.watch/versions/8.0/gdimage#gdimage-is-resource
---
 src/include/image_is_resizable.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/include/image_is_resizable.php b/src/include/image_is_resizable.php
index 526db23..f0ea2ea 100644
--- a/src/include/image_is_resizable.php
+++ b/src/include/image_is_resizable.php
@@ -5,11 +5,11 @@
   if(file_exists($filename))
   {
     $image = Helper::ImageCreateFromGeneral($filename);
-    if(is_resource($image))
+    if(is_resource($image) || $image instanceof \GdImage)
     {
       ImageDestroy($image);
       $result = 1;
     }
   }
   print $result;
-?>
\ No newline at end of file
+?>