Merge branch 'MDL-54647-master' of git://github.com/damyon/moodle

diff --cc lib/filestorage/file_storage.php
index 0c105e2,c3cf07a..a5bc30c
--- 1/lib/filestorage/file_storage.php
--- 2/lib/filestorage/file_storage.php
+++ b/lib/filestorage/file_storage.php
@@@ -403,9 -404,16 +405,16 @@@ class file_storage 
              'filename'  => $file->get_contenthash(),
          );
  
+         if ($forcerefresh) {
+             $existing = $this->get_file($context->id, 'core', 'documentconversion', 0, $path, $file->get_contenthash());
+             if ($existing) {
+                 $existing->delete();
+             }
+         }
+ 
          $convertedfile = $this->create_file_from_pathname($record, $newtmpfile);
          // Cleanup.
 -        remove_dir($uniqdir);
 +        remove_dir($tmp);
          return $convertedfile;
      }