1 files changed, 26 insertions, 2 deletions
diff --git a/app/models/wiki_page.rb b/app/models/wiki_page.rb
index 3dc90edb331..faf3d19d936 100644
--- a/app/models/wiki_page.rb
+++ b/app/models/wiki_page.rb
@@ -65,6 +65,7 @@ class WikiPage
   validates :title, presence: true
   validates :content, presence: true
   validate :validate_path_limits, if: :title_changed?
+  validate :validate_content_size_limit, if: :content_changed?
 
   # The GitLab Wiki instance.
   attr_reader :wiki
@@ -97,6 +98,7 @@ class WikiPage
   def slug
     attributes[:slug].presence || wiki.wiki.preview_slug(title, format)
   end
+  alias_method :id, :slug # required to use build_stubbed
 
   alias_method :to_param, :slug
 
@@ -264,8 +266,8 @@ class WikiPage
     '../shared/wikis/wiki_page'
   end
 
-  def id
-    page.version.to_s
+  def sha
+    page.version&.sha
   end
 
   def title_changed?
@@ -282,6 +284,17 @@ class WikiPage
     end
   end
 
+  def content_changed?
+    if persisted?
+      # gollum-lib always converts CRLFs to LFs in Gollum::Wiki#normalize,
+      # so we need to do the same here.
+      # Also see https://gitlab.com/gitlab-org/gitlab/-/issues/21431
+      raw_content.delete("\r") != page&.text_data
+    else
+      raw_content.present?
+    end
+  end
+
   # Updates the current @attributes hash by merging a hash of params
   def update_attributes(attrs)
     attrs[:title] = process_title(attrs[:title]) if attrs[:title].present?
@@ -391,4 +404,15 @@ class WikiPage
       })
     end
   end
+
+  def validate_content_size_limit
+    current_value = raw_content.to_s.bytesize
+    max_size = Gitlab::CurrentSettings.wiki_page_max_content_bytes
+    return if current_value <= max_size
+
+    errors.add(:content, _('is too long (%{current_value}). The maximum size is %{max_size}.') % {
+      current_value: ActiveSupport::NumberHelper.number_to_human_size(current_value),
+      max_size: ActiveSupport::NumberHelper.number_to_human_size(max_size)
+    })
+  end
 end