Merge pull request rails#55368 from yahonda/pg18-warn-if-pg-gem-less-than-16

Emit a warning when `pg` gem < 1.6.0 is used with PostgreSQL 18+

Author: yahonda

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Emit a warning for pg gem < 1.6.0 when using PostgreSQL 18+
+
+    *Yasuo Honda*
+
 *   Fix `#merge` with `#or` or `#and` and a mixture of attributes and SQL strings resulting in an incorrect query.
 
     ```ruby

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -666,6 +666,9 @@ def check_version # :nodoc:
         if database_version < 9_03_00 # < 9.3
           raise "Your version of PostgreSQL (#{database_version}) is too old. Active Record supports PostgreSQL >= 9.3."
         end
+        if database_version >= 18_00_00 && Gem::Version.new(PG::VERSION) < Gem::Version.new("1.6.0")
+          warn "pg gem version #{PG::VERSION} is known to be incompatible with PostgreSQL 18+. Please upgrade to pg 1.6.0 or later."
+        end
       end
 
       class << self

activerecord/test/cases/adapters/postgresql/transaction_test.rb

@@ -181,6 +181,9 @@ class Sample < ActiveRecord::Base
     end
 
     test "raises Interrupt when canceling statement via interrupt" do
+      if ActiveRecord::Base.lease_connection.database_version >= 18_00_00 && Gem::Version.new(PG::VERSION) < Gem::Version.new("1.6.0")
+        skip "pg gem version #{PG::VERSION} is known to be incompatible with PostgreSQL 18+. "
+      end
       start_time = Time.now
       thread = Thread.new do
         Sample.transaction do