If an index can't be found by column, use the index name.

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.

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 5b8de184fe..9d624a6648 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -687,6 +687,12 @@ module ActiveRecord
           index_name = index_name(table_name, options)
 
           unless index_name_exists?(table_name, index_name, true)
+            if options.has_key? :name
+              options_without_column = options.dup
+              options_without_column.delete :column
+              index_name_without_column = index_name(table_name, options_without_column)
+              return index_name_without_column if index_name_exists?(table_name, index_name_without_column, false)
+            end
             raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"
           end