Improve EE compatibility with protected branch access levels.

1. Change a few incorrect `access_level` to `access_levels.first` that
   were missed in e805a647.

2. `API::Entities` can iterate over all access levels instead of just
   the first one. This makes no difference to CE, and makes it more compatible
   with EE.

lib/api/entities.rb

@@ -129,12 +129,14 @@ module API
 
       expose :developers_can_push do |repo_branch, options|
         project = options[:project]
-        project.protected_branches.matching(repo_branch.name).any? { |protected_branch| protected_branch.push_access_levels.first.access_level == Gitlab::Access::DEVELOPER }
+        access_levels = project.protected_branches.matching(repo_branch.name).map(&:push_access_levels).flatten
+        access_levels.any? { |access_level| access_level.access_level == Gitlab::Access::DEVELOPER }
       end
 
       expose :developers_can_merge do |repo_branch, options|
         project = options[:project]
-        project.protected_branches.matching(repo_branch.name).any? { |protected_branch| protected_branch.merge_access_levels.first.access_level == Gitlab::Access::DEVELOPER }
+        access_levels = project.protected_branches.matching(repo_branch.name).map(&:merge_access_levels).flatten
+        access_levels.any? { |access_level| access_level.access_level == Gitlab::Access::DEVELOPER }
       end
     end
 

lib/gitlab/user_access.rb

@@ -32,7 +32,7 @@ module Gitlab
       if project.protected_branch?(ref)
         return true if project.empty_repo? && project.user_can_push_to_empty_repo?(user)
 
-        access_levels = project.protected_branches.matching(ref).map(&:push_access_level)
+        access_levels = project.protected_branches.matching(ref).map(&:push_access_levels).flatten
         access_levels.any? { |access_level| access_level.check_access(user) }
       else
         user.can?(:push_code, project)
@@ -43,7 +43,7 @@ module Gitlab
       return false unless user
 
       if project.protected_branch?(ref)
-        access_levels = project.protected_branches.matching(ref).map(&:merge_access_level)
+        access_levels = project.protected_branches.matching(ref).map(&:merge_access_levels).flatten
         access_levels.any? { |access_level| access_level.check_access(user) }
       else
         user.can?(:push_code, project)

spec/services/git_push_service_spec.rb

@@ -227,7 +227,7 @@ describe GitPushService, services: true do
         expect(project.default_branch).to eq("master")
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.first.push_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
         expect(project.protected_branches.first.merge_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
       end
 
@@ -249,7 +249,7 @@ describe GitPushService, services: true do
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
 
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.last.push_access_level.access_level).to eq(Gitlab::Access::DEVELOPER)
+        expect(project.protected_branches.last.push_access_levels.first.access_level).to eq(Gitlab::Access::DEVELOPER)
         expect(project.protected_branches.last.merge_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
       end
 
@@ -260,7 +260,7 @@ describe GitPushService, services: true do
         expect(project.default_branch).to eq("master")
         execute_service(project, user, @blankrev, 'newrev', 'refs/heads/master' )
         expect(project.protected_branches).not_to be_empty
-        expect(project.protected_branches.first.push_access_level.access_level).to eq(Gitlab::Access::MASTER)
+        expect(project.protected_branches.first.push_access_levels.first.access_level).to eq(Gitlab::Access::MASTER)
         expect(project.protected_branches.first.merge_access_levels.first.access_level).to eq(Gitlab::Access::DEVELOPER)
       end