auth_source_ldaps controller test sets account_password to nil to test missing parameter
The test "AuthSourceLdapsControllerTest#test_0001_blank account_password submitted does not erase existing account_password" wasn't updated in commit 2348fc8e (#2943, #11387) to test the difference between a missing account_password parameter and an empty string parameter.
account_password => nil into parameters and then tests that the password is unchanged. Under Rails 5.0, nil is changed to an empty string (because it's form encoded) but under 4.2 it's passed through as
nil (which isn't really possible in form encoding). This causes a failure on 5.0 as it resets the password from the original
AuthSourceLdapsControllerTest#test_0001_blank account_password submitted does not erase existing account_password [test/controllers/auth_source_ldaps_controller_test.rb:82]:
The test should have been updated like other controllers to test with a missing account_password (which should not change the password) and an empty string account_password (which should set it to an empty string). It shouldn't test a
fixes #18489 - test AuthSourceLdap missing and blank passwords
After 2348fc8e, providing an empty password during update would erase
the existing password. Other resource type tests were updated, but not
AuthSourceLdap, so these now reflect the current behaviour.
These started failing on Rails 5 as the test params passed converted a
value of nil (not really possible) to an empty string, causing the
password to be blanked. On develop, the original password was nil
and the update to another nil value was a no-op.