From a9d54eaa97e4691f5df84ef56ddca6b83b801d9b Mon Sep 17 00:00:00 2001
From: Luke Towers <github@luketowers.ca>
Date: Thu, 15 Oct 2020 09:48:46 -0600
Subject: [PATCH] Warn about unsupported cache drivers being used for image
 resizing

---
 modules/system/classes/SystemController.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/modules/system/classes/SystemController.php b/modules/system/classes/SystemController.php
index 2f7ac2418..1b36c7b49 100644
--- a/modules/system/classes/SystemController.php
+++ b/modules/system/classes/SystemController.php
@@ -1,6 +1,7 @@
 <?php namespace System\Classes;
 
 use Lang;
+use Config;
 use Response;
 use Exception;
 use SystemException;
@@ -63,6 +64,11 @@ class SystemController extends ControllerBase
         } catch (SystemException $ex) {
             // If the resizing failed with a SystemException, it was most
             // likely because it is in progress or has already finished
+            // although it could also be because the cache system used to store
+            // configuration data is broken
+            if (Config::get('cache.default', 'file') === 'array') {
+                throw new Exception('Image resizing requires a persistent cache driver, "array" is not supported. Try changing config/cache.php -> default to a persistent cache driver.');
+            }
         } catch (Exception $ex) {
             // If it failed for any other reason, restore the config so that
             // the resizer route will continue to work until it succeeds