Fix `pod repo push --help`

Fixes #5211

lib/cocoapods/command/repo/push.rb

@@ -38,7 +38,7 @@ module Pod
           @allow_warnings = argv.flag?('allow-warnings')
           @local_only = argv.flag?('local-only')
           @repo = argv.shift_argument
-          @source = config.sources_manager.sources([@repo]).first
+          @source = config.sources_manager.sources([@repo]).first unless @repo.nil?
           @source_urls = argv.option('sources', config.sources_manager.all.map(&:url).join(',')).split(',')
           @podspec = argv.shift_argument
           @use_frameworks = !argv.flag?('use-libraries')

spec/unit/command_spec.rb

@@ -3,20 +3,21 @@ require File.expand_path('../../spec_helper', __FILE__)
 module Pod
   describe Command do
     it 'returns the proper command class' do
-      Command.parse(%w(install      )).should.be.instance_of Command::Install
-      Command.parse(%w(list         )).should.be.instance_of Command::List
-      Command.parse(%w(outdated     )).should.be.instance_of Command::Outdated
-      Command.parse(%w(repo         )).should.be.instance_of Command::Repo::List
-      Command.parse(%w(repo add     )).should.be.instance_of Command::Repo::Add
-      Command.parse(%w(repo lint    )).should.be.instance_of Command::Repo::Lint
-      Command.parse(%w(repo list    )).should.be.instance_of Command::Repo::List
-      Command.parse(%w(repo update  )).should.be.instance_of Command::Repo::Update
-      Command.parse(%w(repo remove  )).should.be.instance_of Command::Repo::Remove
-      Command.parse(%w(setup        )).should.be.instance_of Command::Setup
-      Command.parse(%w(spec create  )).should.be.instance_of Command::Spec::Create
-      Command.parse(%w(spec lint    )).should.be.instance_of Command::Spec::Lint
-      Command.parse(%w(init         )).should.be.instance_of Command::Init
-      Command.parse(%w(env          )).should.be.instance_of Command::Env
+      Command.parse(%w(install         )).should.be.instance_of Command::Install
+      Command.parse(%w(list            )).should.be.instance_of Command::List
+      Command.parse(%w(outdated        )).should.be.instance_of Command::Outdated
+      Command.parse(%w(repo            )).should.be.instance_of Command::Repo::List
+      Command.parse(%w(repo add        )).should.be.instance_of Command::Repo::Add
+      Command.parse(%w(repo lint       )).should.be.instance_of Command::Repo::Lint
+      Command.parse(%w(repo list       )).should.be.instance_of Command::Repo::List
+      Command.parse(%w(repo update     )).should.be.instance_of Command::Repo::Update
+      Command.parse(%w(repo remove     )).should.be.instance_of Command::Repo::Remove
+      Command.parse(%w(repo push --help)).should.be.instance_of Command::Repo::Push
+      Command.parse(%w(setup           )).should.be.instance_of Command::Setup
+      Command.parse(%w(spec create     )).should.be.instance_of Command::Spec::Create
+      Command.parse(%w(spec lint       )).should.be.instance_of Command::Spec::Lint
+      Command.parse(%w(init            )).should.be.instance_of Command::Init
+      Command.parse(%w(env             )).should.be.instance_of Command::Env
     end
   end
 end