From 69a8836910789d73f3aac86a55957d124885cd2d Mon Sep 17 00:00:00 2001
From: Samuel Amoser <samuel.amoser@oetiker.ch>
Date: Tue, 18 Aug 2020 15:16:07 +0200
Subject: [PATCH] PATCH: Prevents calling strpos with empty needle

We happen to run into this warning:
```
[Warning] strpos(): Empty needle
Line 2618 in ./framework/i18n/i18n.php

2618    strpos($theme, (string)Config::inst()->get('SSViewer', 'theme')) === 0
```
I suggest to test the needle against emptyness before invoking strpos.
---
 i18n/i18n.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/i18n/i18n.php b/i18n/i18n.php
index 909d3d1df..35c0c8723 100644
--- a/i18n/i18n.php
+++ b/i18n/i18n.php
@@ -2614,8 +2614,10 @@ class i18n extends SS_Object implements TemplateGlobalProvider, Flushable {
 				$themesBase = Director::baseFolder() . '/themes';
 				if(is_dir($themesBase)) {
 					foreach(scandir($themesBase) as $theme) {
+						$themename = (string)Config::inst()->get('SSViewer', 'theme');
 						if(
-							strpos($theme, (string)Config::inst()->get('SSViewer', 'theme')) === 0
+							!empty($themename)
+							&& strpos($theme, $themename) === 0
 							&& file_exists("{$themesBase}/{$theme}/lang/")
 						) {
 							$filename = $adapter->getFilenameForLocale($locale);