From a94cbf81e1fcef1f50af631e3b1117c2bf68df7f Mon Sep 17 00:00:00 2001
From: hsbt <hsbt@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 4 Dec 2018 08:00:57 +0000
Subject: [PATCH] Merge rubygems master@221bdea

  * Fixed https://github.com/rubygems/rubygems/pull/2506

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66188 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 lib/rubygems/specification.rb           |  2 +-
 test/rubygems/test_gem_specification.rb | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/rubygems/specification.rb b/lib/rubygems/specification.rb
index 7eaa509d2b..b620021c5c 100644
--- a/lib/rubygems/specification.rb
+++ b/lib/rubygems/specification.rb
@@ -2693,7 +2693,7 @@ class Gem::Specification < Gem::BasicSpecification
     @version = Gem::Version.create(version)
     # skip to set required_ruby_version when pre-released rubygems.
     # It caused to raise CircularDependencyError
-    if @version.prerelease? && @name.strip != "rubygems"
+    if @version.prerelease? && (@name.nil? || @name.strip != "rubygems")
       self.required_rubygems_version = '> 1.3.1'
     end
     invalidate_memoized_attributes
diff --git a/test/rubygems/test_gem_specification.rb b/test/rubygems/test_gem_specification.rb
index 4fbb1e73e0..7a26d5918e 100644
--- a/test/rubygems/test_gem_specification.rb
+++ b/test/rubygems/test_gem_specification.rb
@@ -1345,6 +1345,16 @@ dependencies: []
     assert_equal '/path/to/file', e.file_path
   end
 
+  def test_initialize_prerelease_version_before_name
+    spec = Gem::Specification.new do |s|
+      s.version = '1.0.0.dev'
+      s.name = 'a'
+    end
+
+    assert_equal "a", spec.name
+    assert_equal "1.0.0.dev", spec.version.to_s
+  end
+
   def test__dump
     @a2.platform = Gem::Platform.local
     @a2.instance_variable_set :@original_platform, 'old_platform'