Return plausible isReadable() default impl for ext storage

When an ext storage doesn't implement isReadable(), always returning
true made the file scanner believe that the file exists and creates a
cache entry with the size zero.

This fix makes the default impl of isReadable() use file_exists().

Backport of a49e873d3fa513136bfdf1d71bbc2bbcd61d3650

diff --git a/apps/files_external/lib/streamwrapper.php b/apps/files_external/lib/streamwrapper.php
index 4a63dfb6e0277b6c6fd9d5286fe7a42257ba7f9f..a086f411f573b0005c53d82ca9df9e1699687043 100644 (file)
--- a/apps/files_external/lib/streamwrapper.php
+++ b/apps/files_external/lib/streamwrapper.php
@@ -42,11 +42,16 @@ abstract class StreamWrapper extends Common {
        }
 
        public function isReadable($path) {
-               return true; //not properly supported
+               // at least check whether it exists
+               // subclasses might want to implement this more thoroughly
+               return $this->file_exists($path);
        }
 
        public function isUpdatable($path) {
-               return true; //not properly supported
+               // at least check whether it exists
+               // subclasses might want to implement this more thoroughly
+               // a non-existing file/folder isn't updatable
+               return $this->file_exists($path);
        }
 
        public function file_exists($path) {