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, 16 insertions, 0 deletions

diff --git a/activerecord/test/cases/migration_test.rb b/activerecord/test/cases/migration_test.rb
index 960d28fcf5..6f90500189 100644
--- a/activerecord/test/cases/migration_test.rb
+++ b/activerecord/test/cases/migration_test.rb
@@ -462,6 +462,22 @@ class ReservedWordsMigrationTest < ActiveRecord::TestCase
   end
 end
 
+class ExplicitlyNamedIndexMigrationTest < ActiveRecord::TestCase
+  def test_drop_index_by_name
+    connection = Person.connection
+    connection.create_table :values, force: true do |t|
+      t.integer :value
+    end
+
+    assert_nothing_raised ArgumentError do
+      connection.add_index :values, :value, name: 'a_different_name'
+      connection.remove_index :values, column: :value, name: 'a_different_name'
+    end
+
+    connection.drop_table :values rescue nil
+  end
+end
+
 if ActiveRecord::Base.connection.supports_bulk_alter?
   class BulkAlterTableMigrationsTest < ActiveRecord::TestCase
     def setup