From c88ba8e255d1a358ed5121fa645b165b28a4e25f Mon Sep 17 00:00:00 2001
From: Holger Just <holger@plan.io>
Date: Thu, 12 Oct 2023 19:08:16 +0200
Subject: [PATCH 1/2] Fix watcher handling on unsaved objects

---
 .../lib/acts_as_watchable.rb                  | 20 +++++++---
 test/unit/watcher_test.rb                     | 37 +++++++++++++++++++
 2 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb b/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb
index 907535ec7a..2bd13cedcf 100644
--- a/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb
+++ b/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb
@@ -44,17 +44,25 @@ def addable_watcher_users
 
         # Adds user as a watcher
         def add_watcher(user)
-          # Rails does not reset the has_many :through association
-          watcher_users.reset
-          self.watchers << Watcher.new(:user => user)
+          if persisted?
+            # Rails does not reset the has_many :through association
+            watcher_users.reset
+            self.watchers << Watcher.new(:user => user)
+          else
+            self.watcher_users << user
+          end
         end
 
         # Removes user from the watchers list
         def remove_watcher(user)
           return nil unless user && (user.is_a?(User) || user.is_a?(Group))
-          # Rails does not reset the has_many :through association
-          watcher_users.reset
-          watchers.where(:user_id => user.id).delete_all
+          if persisted?
+            # Rails does not reset the has_many :through association
+            watcher_users.reset
+            watchers.where(:user_id => user.id).delete_all
+          else
+            watcher_users.delete(user)
+          end
         end
 
         # Adds/removes watcher
diff --git a/test/unit/watcher_test.rb b/test/unit/watcher_test.rb
index 1e95be2f62..a9a7534a6c 100644
--- a/test/unit/watcher_test.rb
+++ b/test/unit/watcher_test.rb
@@ -124,6 +124,43 @@ def test_addable_watcher_users
     end
   end
 
+  def test_add_watcher_with_unsaved_object
+    issue = Issue.new(project: Project.find(1), tracker_id: 1, subject: "test", author: User.find(2))
+    refute issue.persisted?
+
+    issue.add_watcher(@user)
+    assert issue.watched_by?(@user)
+
+    assert_equal [@user.id], issue.watcher_user_ids
+    assert_equal [@user], issue.watcher_users
+
+    assert_equal [nil], issue.watcher_ids
+    assert_equal 1, issue.watchers.size
+
+    issue.save!
+    assert 1, Watcher.where(watchable: issue).count
+  end
+
+  def test_remove_watcher_with_unsaved_object
+    issue = Issue.new(project: Project.find(1), tracker_id: 1, subject: "test", author: User.find(2))
+    refute issue.persisted?
+
+    issue.add_watcher(@user)
+    assert_equal [@user], issue.watcher_users
+
+    issue.remove_watcher(@user)
+    refute issue.watched_by?(@user)
+
+    assert_equal [], issue.watcher_user_ids
+    assert_equal [], issue.watcher_users
+
+    assert_equal [], issue.watcher_ids
+    assert_equal [], issue.watchers
+
+    issue.save!
+    assert 0, Watcher.where(watchable: issue).count
+  end
+
   def test_addable_watcher_users_should_not_include_user_that_cannot_view_the_object
     issue = Issue.new(:project => Project.find(1), :is_private => true)
     assert_nil issue.addable_watcher_users.detect {|user| user.is_a?(User) && !issue.visible?(user)}
-- 
2.39.2