PostgreSQL adapter sets invalid value "panic" for client_min_messages

[bblack]

This has been a problem for us from 50.0 all the way up to 52.7. I see from the source in 60.x this may not be an issue anymore.

The postgresql docs (for pg versions that support client_min_messages, i.e. 10 through 13) specify the valid values for client_min_messages:

Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, LOG, NOTICE, WARNING, and ERROR.

Yet, the postgres adapter here (up to 52.7 at least) tries setting it to "panic":

activerecord-jdbc-adapter/lib/arjdbc/postgresql/adapter.rb

Lines 206 to 219 in 1100221

	# Enable standard-conforming strings if available.
	def standard_conforming_strings=(enable)
	client_min_messages = self.client_min_messages
	begin
	self.client_min_messages = 'panic'
	value = enable ? "on" : "off"
	execute("SET standard_conforming_strings = #{value}", 'SCHEMA')
	@standard_conforming_strings = ( value == "on" )
	rescue
	@standard_conforming_strings = :unsupported
	ensure
	self.client_min_messages = client_min_messages
	end
	end

activerecord-jdbc-adapter/lib/arjdbc/postgresql/adapter.rb

Lines 221 to 235 in 1100221

	def standard_conforming_strings?
	if @standard_conforming_strings.nil?
	client_min_messages = self.client_min_messages
	begin
	self.client_min_messages = 'panic'
	value = select_one('SHOW standard_conforming_strings', 'SCHEMA')['standard_conforming_strings']
	@standard_conforming_strings = ( value == "on" )
	rescue
	@standard_conforming_strings = :unsupported
	ensure
	self.client_min_messages = client_min_messages
	end
	end
	@standard_conforming_strings == true # return false if :unsupported
	end

In our app this didn't actually present a problem until we upgraded postgres to either 11 or 12 (we're on 12 now), so perhaps "panic" actually was an acceptable value in a prior version, despite the docs. In any case, it's not an acceptable value now.

The effect is that trying to set it to "panic" raises an error, which is rescued, and @standard_conforming_strings is incorrectly set to :unsupported, which causes problems later when our app constructs properly-escaped queries.

We've worked around it by monkeypatching these functions to remove the extra bits:

module ArJdbc
  module PostgreSQL
    def standard_conforming_strings=(enable)
      value = enable ? "on" : "off"
      execute("SET standard_conforming_strings = #{value}", 'SCHEMA')
      @standard_conforming_strings = ( value == "on" )
    end

    def standard_conforming_strings?
      value = select_one('SHOW standard_conforming_strings', 'SCHEMA')['standard_conforming_strings']
      @standard_conforming_strings = ( value == "on" )
    end
  end
end

As I said, it looks like this may be fixed in 60.x. Can this be backported to 52.x (or further)?

[bblack]

This has been a problem for us from 50.0 all the way up to 52.7. I see from the source in 60.x this may not be an issue anymore.

Actually, this was a problem before 50.x when we were on Rails 4 too.