Allow guests users to access project releases

This is step one of resolving
https://gitlab.com/gitlab-org/gitlab-ce/issues/56838.

Here is what changed:
- Revert the security fix from bdee9e8412d.
- Do not leak repository information (tag name, commit) to guests in API
responses.
- Do not include links to source code in API responses for users that do
not have download_code access.
- Show Releases in sidebar for guests.
- Do not display links to source code under Assets for users that do not
have download_code access.

GET ':id/releases/:tag_name' still do not allow guests to access
releases. This is to prevent guessing tag existence.

1 files changed, 3 insertions, 2 deletions

diff --git a/app/helpers/projects_helper.rb b/app/helpers/projects_helper.rb
index 2ac90eb8d9f..8977ccaa9d8 100644
--- a/app/helpers/projects_helper.rb
+++ b/app/helpers/projects_helper.rb
@@ -318,8 +318,9 @@ module ProjectsHelper
   def get_project_nav_tabs(project, current_user)
     nav_tabs = [:home]
 
-    if !project.empty_repo? && can?(current_user, :download_code, project)
-      nav_tabs << [:files, :commits, :network, :graphs, :forks, :releases]
+    unless project.empty_repo?
+      nav_tabs << [:files, :commits, :network, :graphs, :forks] if can?(current_user, :download_code, project)
+      nav_tabs << :releases if can?(current_user, :read_release, project)
     end
 
     if project.repo_exists? && can?(current_user, :read_merge_request, project)