Merge pull request #10713 from senny/10693_fix_primary_key_option_on_has_many

Fix the `:primary_key` option for `has_many` associations.
Conflicts:
	activerecord/CHANGELOG.md
	activerecord/lib/active_record/associations/has_many_association.rb

4 files changed, 15 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index ebd1a3424a..29d218277f 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,10 @@
 ## unreleased ##
 
+*   Fix the `:primary_key` option for `has_many` associations.
+    Fixes #10693.
+
+    *Yves Senn*
+
 *   fixes bug introduced by #3329.  Now, when autosaving associations,
     deletions happen before inserts and saves.  This prevents a 'duplicate
     unique value' database error that would occur if a record being created had
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index 059e6c77bc..dab57bab88 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -89,8 +89,7 @@ module ActiveRecord
             records.each { |r| r.destroy }
             update_counter(-records.length) unless inverse_updates_counter_cache?
           else
-            keys  = records.map { |r| r[reflection.association_primary_key] }
-            scope = scoped.where(reflection.association_primary_key => keys)
+            scope = self.scope.where(reflection.klass.primary_key => records)
 
             if method == :delete_all
               update_counter(-scope.delete_all)
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 869ec1e4b8..8fd9de07c9 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1492,6 +1492,14 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal david.essays, Essay.find_all_by_writer_id("David")
   end
 
+  def test_has_many_assignment_with_custom_primary_key
+    david = people(:david)
+
+    assert_equal ["A Modest Proposal"], david.essays.map(&:name)
+    david.essays = [Essay.create!(name: "Remote Work" )]
+    assert_equal ["Remote Work"], david.essays.map(&:name)
+  end
+
   def test_blank_custom_primary_key_on_new_record_should_not_run_queries
     author = Author.new
     assert !author.essays.loaded?
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index 07c529d685..3a7a730a1a 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -27,6 +27,7 @@ class Person < ActiveRecord::Base
 
   has_many :agents_posts,         :through => :agents,       :source => :posts
   has_many :agents_posts_authors, :through => :agents_posts, :source => :author
+  has_many :essays, primary_key: "first_name", foreign_key: "writer_id"
 
   scope :males,   :conditions => { :gender => 'M' }
   scope :females, :conditions => { :gender => 'F' }