Merge rubygems-2.6.12 from rubygems/rubygems.

* Details of changes:
    0090800402/History.txt (L3)

  * I kept ko1's commmit related thread issue. It's not merged 2.6 branch on rubygems.
    1721dfa0ea

  * I removed test_realworld_default_gem from rubygems-2.6.12. It fails on
    Ruby trunk. Because it's differences of test suite and environment.
    https://github.com/rubygems/rubygems/pull/1899

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58530 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/rubygems/test_gem_commands_sources_command.rb

@@ -108,6 +108,58 @@ source #{@gem_repo} already present in the cache
     assert_equal '', @ui.error
   end
 
+  def test_execute_add_redundant_source_trailing_slash
+    # Remove pre-existing gem source (w/ slash)
+    repo_with_slash = "http://gems.example.com/"
+    @cmd.handle_options %W[--remove #{repo_with_slash}]
+    use_ui @ui do
+      @cmd.execute
+    end
+    source = Gem::Source.new repo_with_slash
+    assert_equal false, Gem.sources.include?(source)
+
+    expected = <<-EOF
+#{repo_with_slash} removed from sources
+    EOF
+
+    assert_equal expected, @ui.output
+    assert_equal '', @ui.error
+
+    # Re-add pre-existing gem source (w/o slash)
+    repo_without_slash = "http://gems.example.com"
+    @cmd.handle_options %W[--add #{repo_without_slash}]
+    use_ui @ui do
+      @cmd.execute
+    end
+    source = Gem::Source.new repo_without_slash
+    assert_equal true, Gem.sources.include?(source)
+
+    expected = <<-EOF
+http://gems.example.com/ removed from sources
+http://gems.example.com added to sources
+    EOF
+
+    assert_equal expected, @ui.output
+    assert_equal '', @ui.error
+
+    # Re-add original gem source (w/ slash)
+    @cmd.handle_options %W[--add #{repo_with_slash}]
+    use_ui @ui do
+      @cmd.execute
+    end
+    source = Gem::Source.new repo_with_slash
+    assert_equal true, Gem.sources.include?(source)
+
+    expected = <<-EOF
+http://gems.example.com/ removed from sources
+http://gems.example.com added to sources
+source http://gems.example.com/ already present in the cache
+    EOF
+
+    assert_equal expected, @ui.output
+    assert_equal '', @ui.error 
+  end
+
   def test_execute_add_http_rubygems_org
     http_rubygems_org = 'http://rubygems.org'