Check return of fopen() before using it

Fix #9968

diff --git a/lib/private/preview.php b/lib/private/preview.php
index aeb9806904a7b04680ed3e16ac01777e4588492c..cc15ab84fe75f3bd92e12b949a2d42e162322c1f 100755 (executable)
--- a/lib/private/preview.php
+++ b/lib/private/preview.php
@@ -477,12 +477,15 @@ class Preview {
                $cached = $this->isCached($fileId);
                if ($cached) {
                        $stream = $this->userView->fopen($cached, 'r');
-                       $image = new \OC_Image();
-                       $image->loadFromFileHandle($stream);
-                       $this->preview = $image->valid() ? $image : null;
+                       $this->preview = null;
+                       if ($stream) {
+                               $image = new \OC_Image();
+                               $image->loadFromFileHandle($stream);
+                               $this->preview = $image->valid() ? $image : null;
 
-                       $this->resizeAndCrop();
-                       fclose($stream);
+                               $this->resizeAndCrop();
+                               fclose($stream);
+                       }
                }
 
                if (is_null($this->preview)) {