1 files changed, 6 insertions, 4 deletions
diff --git a/vendor/sabre/dav/lib/DAV/Browser/GuessContentType.php b/vendor/sabre/dav/lib/DAV/Browser/GuessContentType.php
index 7466babb3..b07103db9 100644
--- a/vendor/sabre/dav/lib/DAV/Browser/GuessContentType.php
+++ b/vendor/sabre/dav/lib/DAV/Browser/GuessContentType.php
@@ -85,10 +85,12 @@ class GuessContentType extends DAV\ServerPlugin
      */
     protected function getContentType($fileName)
     {
-        // Just grabbing the extension
-        $extension = strtolower(substr($fileName, strrpos($fileName, '.') + 1));
-        if (isset($this->extensionMap[$extension])) {
-            return $this->extensionMap[$extension];
+        if (null !== $fileName) {
+            // Just grabbing the extension
+            $extension = strtolower(substr($fileName, strrpos($fileName, '.') + 1));
+            if (isset($this->extensionMap[$extension])) {
+                return $this->extensionMap[$extension];
+            }
         }
 
         return 'application/octet-stream';