? .directory
? drupal-818818-D6.patch
? drupal-818818-D6_0.patch
Index: includes/file.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/file.inc,v
retrieving revision 1.121.2.12
diff -u -p -r1.121.2.12 file.inc
--- includes/file.inc	11 May 2010 09:49:58 -0000	1.121.2.12
+++ includes/file.inc	21 Jun 2010 22:55:40 -0000
@@ -263,7 +263,33 @@ function file_copy(&$source, $dest = 0, 
       return FALSE;
     }
 
-    if (!@copy($source, $dest)) {
+    // Perform the replace operation. copy() is not atomic but rename() is.
+    // Since there could be mutiple processes writing to the same file the best
+    // option is to create a temp file in the same directory and then rename it
+    // to the final filename.
+    $result = FALSE;
+    if ($replace == FILE_EXISTS_REPLACE) {
+      // Get temp filename
+      $temp_name = tempnam(realpath(dirname($dest)), 'file');
+      // Place new contents in temp file
+      if ($temp_file && @copy($source, $temp_name)) {
+        // Try the rename opperation
+        if (!$result = @rename($temp_name, $dest)) {
+          // Unlink and try again for windows since rename on windows does not
+          // replace the file if it already exists.
+          @unlink($dest);
+          $result = @rename($temp_name, $dest);
+        }
+      }
+      else {
+        $result = FALSE;
+      }
+    }
+    // Perform the copy operation.
+    else {
+      $result = @copy($source, $dest);
+    }
+    if ($result === FALSE) {
       drupal_set_message(t('The selected file %file could not be copied.', array('%file' => $source)), 'error');
       return 0;
     }