commit 11a75d0f2fea50ab4f35e99a7b584c450ea0e634
Author: Yossef Mendelssohn <ymendel@pobox.com>
Date:   Sat May 2 11:44:52 2009 -0500
 
    Made prerelease gems stick to the release number for satisfying ~>
    
    Since 1.1.pre is < 1.1, it would fail ~> 1.1
    Added Gem::Version#release for convenience and cleanliness
 
diff --git a/lib/rubygems/requirement.rb b/lib/rubygems/requirement.rb
index ba6b890..8c2a196 100644
--- a/lib/rubygems/requirement.rb
+++ b/lib/rubygems/requirement.rb
@@ -26,7 +26,7 @@ class Gem::Requirement
     "<"  =>  lambda { |v, r| v < r },
     ">=" =>  lambda { |v, r| v >= r },
     "<=" =>  lambda { |v, r| v <= r },
-    "~>" =>  lambda { |v, r| v >= r && v < r.bump }
+    "~>" =>  lambda { |v, r| v = v.release; v >= r && v < r.bump }
   }
 
   OP_RE = OPS.keys.map{ |k| Regexp.quote k }.join '|'
diff --git a/lib/rubygems/version.rb b/lib/rubygems/version.rb
index d996538..4e979a5 100644
--- a/lib/rubygems/version.rb
+++ b/lib/rubygems/version.rb
@@ -160,6 +160,16 @@ class Gem::Version
   def prerelease?
     parts.any? { |part| part.alpha? }
   end
+  
+  ##
+  # The release for this version (e.g. 1.2.0.a -> 1.2.0)
+  # Non-prerelease versions return themselves
+  def release
+    return self unless prerelease?
+    rel_parts = parts.dup
+    rel_parts.pop while rel_parts.any? { |part| part.alpha? }
+    self.class.new(rel_parts.join('.'))
+  end
 
   def yaml_initialize(tag, values)
     self.version = values['version']
diff --git a/test/test_gem_version.rb b/test/test_gem_version.rb
index 29b8b5b..d87245f 100644
--- a/test/test_gem_version.rb
+++ b/test/test_gem_version.rb
@@ -199,6 +199,13 @@ class TestGemVersion < RubyGemTestCase
     refute Gem::Version.new('2.9').prerelease?
     refute Gem::Version.new('22.1.50.0').prerelease?
   end
+  
+  def test_release
+    assert_equal Gem::Version.new('1.2.0'), Gem::Version.new('1.2.0.a').release
+    assert_equal Gem::Version.new('1.1'),   Gem::Version.new('1.1.rc10').release
+    assert_equal Gem::Version.new('1.9.3'), Gem::Version.new('1.9.3.alpha.5').release
+    assert_equal Gem::Version.new('1.9.3'), Gem::Version.new('1.9.3').release
+  end
 
   def test_satisfied_by_eh_boxed
     assert_inadequate("1.3", "~> 1.4")
@@ -212,6 +219,11 @@ class TestGemVersion < RubyGemTestCase
     assert_adequate(  "1.4.5", "~> 1.4.4")
     assert_inadequate("1.5",   "~> 1.4.4")
     assert_inadequate("2.0",   "~> 1.4.4")
+    
+    assert_inadequate("1.1.pre", "~> 1.0.0")
+    assert_adequate(  "1.1.pre", "~> 1.1")
+    assert_inadequate("2.0.a",   "~> 1.0")
+    assert_adequate(  "2.0.a",   "~> 2.0")
   end
 
   def test_satisfied_by_eh_multiple