rails/rails — pull request #8868 by tehgeekmeister (2013-01-10 08:52:04+00:00)
Title: Use the index name explicitly provided in a migration when reverting.

schema_statements uses the column name by default to construct the index name, and then raises an exception if it doesn't exist, even if the name option is specified, which causes #8858. this commit makes index_name_for_remove fall back to constructing the index name to remove based on the name option.