X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/2af0840ff314f9d1e0265a4a1b50fc6db4af9047..ec9d2fde783796829a84655387e1810ea4b5e642:/app/models/relation.rb

diff --git a/app/models/relation.rb b/app/models/relation.rb
index 3d3c317aa..cb9621822 100644
--- a/app/models/relation.rb
+++ b/app/models/relation.rb
@@ -246,8 +246,10 @@ class Relation < ActiveRecord::Base
 
       # use reflection to look up the appropriate class
       model = Kernel.const_get(m[0].capitalize)
-      # get the element with that ID
-      element = model.find_by(:id => m[1])
+      # get the element with that ID. and, if found, lock the element to
+      # ensure it can't be deleted until after the current transaction
+      # commits.
+      element = model.lock("for share").find_by(:id => m[1])
 
       # and check that it is OK to use.
       unless element && element.visible? && element.preconditions_ok?