Fix removing published_at for a scheduled draft (#18682)

* Fix removing published_at for a scheduled draft

* Fix Article spec

app/models/article.rb

@@ -790,10 +790,11 @@ class Article < ApplicationRecord
   def correct_published_at?
     return unless changes["published_at"]
 
-    # for drafts (that were never published before) or scheduled articles => allow future or current dates
+    # for drafts (that were never published before) or scheduled articles
+    # => allow future or current dates, or no published_at
     if !published_at_was || published_at_was > Time.current
       # for articles published_from_feed (exported from rss) we allow past published_at
-      if (!published_at || published_at < 15.minutes.ago) && !published_from_feed
+      if (published_at && published_at < 15.minutes.ago) && !published_from_feed
         errors.add(:published_at, I18n.t("models.article.future_or_current_published_at"))
       end
     else

config/locales/models/en.yml

@@ -21,7 +21,8 @@ en:
       must_not_have_spaces: must not have spaces
       published: Published
       unique_url: has already been taken. Email %{email} for further details.
-      future_or_current_published_at: only future or current published_at allowed when publishing an article
+      future_or_current_published_at: only future or current published_at allowed
+
       immutable_published_at: updating published_at for articles that have already been published is not allowed
       mention_too_many:
         one: You cannot mention more than %{count} users in a post!

config/locales/models/fr.yml

@@ -21,7 +21,7 @@ fr:
       must_not_have_spaces: must not have spaces
       published: Published
       unique_url: has already been taken. Email %{email} for further details.
-      future_or_current_published_at: only future or current published_at allowed when publishing an article
+      future_or_current_published_at: only future or current published_at allowed
       immutable_published_at: updating published_at for articles that have already been published is not allowed
       mention_too_many:
         one: You cannot mention more than %{count} users in a post!

spec/models/article_spec.rb

@@ -514,14 +514,14 @@ RSpec.describe Article, type: :model do
       article2 = build(:article, published_at: 10.days.ago, published: true)
       expect(article2.valid?).to be false
       expect(article2.errors[:published_at])
-        .to include("only future or current published_at allowed when publishing an article")
+        .to include("only future or current published_at allowed")
     end
 
     it "doesn't allow recent published_at when publishing on create" do
       article2 = build(:article, published_at: 1.hour.ago, published: true)
       expect(article2.valid?).to be false
       expect(article2.errors[:published_at])
-        .to include("only future or current published_at allowed when publishing an article")
+        .to include("only future or current published_at allowed")
     end
 
     it "allows recent published_at when publishing on create" do
@@ -529,6 +529,12 @@ RSpec.describe Article, type: :model do
       expect(article2.valid?).to be true
     end
 
+    it "allows removing published_at when updating a scheduled draft" do
+      scheduled_draft = create(:article, published: false, published_at: 1.day.from_now)
+      scheduled_draft.published_at = nil
+      expect(scheduled_draft).to be_valid
+    end
+
     context "when unpublishing" do
       let!(:published_at_was) { article.published_at }