Respect custom primary keys for associations in `Relation#where`

While we query the proper columns, we go through normal handling for
converting the value to a primitive which assumes it should use the
table's primary key. If the association specifies a different value (and
we know that we're working with an association), we should use the
custom primary key instead.

Fixes #18813.

1 files changed, 37 insertions, 1 deletions

diff --git a/activerecord/test/cases/relation/where_test.rb b/activerecord/test/cases/relation/where_test.rb
index 537937decd..6af31017d6 100644
--- a/activerecord/test/cases/relation/where_test.rb
+++ b/activerecord/test/cases/relation/where_test.rb
@@ -5,6 +5,7 @@ require "models/cake_designer"
 require "models/chef"
 require "models/comment"
 require "models/edge"
+require "models/essay"
 require "models/post"
 require "models/price_estimate"
 require "models/topic"
@@ -13,7 +14,7 @@ require "models/vertex"
 
 module ActiveRecord
   class WhereTest < ActiveRecord::TestCase
-    fixtures :posts, :edges, :authors, :binaries
+    fixtures :posts, :edges, :authors, :binaries, :essays
 
     def test_where_copies_bind_params
       author = authors(:david)
@@ -240,5 +241,40 @@ module ActiveRecord
       count = Binary.where(:data => 0).count
       assert_equal 0, count
     end
+
+    def test_where_on_association_with_custom_primary_key
+      author = authors(:david)
+      essay = Essay.where(writer: author).first
+
+      assert_equal essays(:david_modest_proposal), essay
+    end
+
+    def test_where_on_association_with_custom_primary_key_with_relation
+      author = authors(:david)
+      essay = Essay.where(writer: Author.where(id: author.id)).first
+
+      assert_equal essays(:david_modest_proposal), essay
+    end
+
+    def test_where_on_association_with_relation_performs_subselect_not_two_queries
+      author = authors(:david)
+
+      assert_queries(1) do
+        Essay.where(writer: Author.where(id: author.id)).to_a
+      end
+    end
+
+    def test_where_on_association_with_custom_primary_key_with_array_of_base
+      author = authors(:david)
+      essay = Essay.where(writer: [author]).first
+
+      assert_equal essays(:david_modest_proposal), essay
+    end
+
+    def test_where_on_association_with_custom_primary_key_with_array_of_ids
+      essay = Essay.where(writer: ["David"]).first
+
+      assert_equal essays(:david_modest_proposal), essay
+    end
   end
 end