4 files changed, 12 insertions, 3 deletions
diff --git a/lib/mruby/build/command.rb b/lib/mruby/build/command.rb
index 0f18e0e62..0fa4746da 100644
--- a/lib/mruby/build/command.rb
+++ b/lib/mruby/build/command.rb
@@ -30,10 +30,13 @@ module MRuby
     def _run(options, params={})
       return sh command + ' ' + ( options % params ) if NotFoundCommands.key? @command
       begin
+        fiber, $rake_root_fiber = $rake_root_fiber, nil
         sh build.filename(command) + ' ' + ( options % params )
       rescue RuntimeError
         NotFoundCommands[@command] = true
         _run options, params
+      ensure
+        $rake_root_fiber = fiber
       end
     end
   end
diff --git a/mrbgems/mruby-rational/mrbgem.rake b/mrbgems/mruby-rational/mrbgem.rake
index 496082709..15c3429f2 100644
--- a/mrbgems/mruby-rational/mrbgem.rake
+++ b/mrbgems/mruby-rational/mrbgem.rake
@@ -4,5 +4,4 @@ MRuby::Gem::Specification.new('mruby-rational') do |spec|
   spec.summary = 'Rational class'
 
   spec.add_dependency 'mruby-object-ext', core: 'mruby-object-ext'
-  spec.add_dependency 'mruby-numeric-ext', core: 'mruby-numeric-ext'
 end
diff --git a/mrbgems/mruby-rational/mrblib/rational.rb b/mrbgems/mruby-rational/mrblib/rational.rb
index 54324b05f..37e9d8c0f 100644
--- a/mrbgems/mruby-rational/mrblib/rational.rb
+++ b/mrbgems/mruby-rational/mrblib/rational.rb
@@ -69,7 +69,7 @@ class Rational < Numeric
   end
 end
 
-class << Numeric
+class Numeric
   def to_r
     Rational(self, 1)
   end
@@ -83,7 +83,7 @@ end
 def Rational(numerator = 0, denominator = 1)
   a = numerator
   b = denominator
-  a, b = b, a % b until b.zero?
+  a, b = b, a % b until b == 0
   Rational._new(numerator.div(a), denominator.div(a))
 end
 
diff --git a/mrbgems/mruby-rational/test/rational.rb b/mrbgems/mruby-rational/test/rational.rb
index 4d3d36ccc..a65926bfb 100644
--- a/mrbgems/mruby-rational/test/rational.rb
+++ b/mrbgems/mruby-rational/test/rational.rb
@@ -100,3 +100,10 @@ assert 'Float#==(Rational), Float#!=(Rational)' do
   assert_equal_rational(true, -2.0, Rational(4,-2))
   assert_equal_rational(false, 3.3, Rational(13,4))
 end
+
+assert 'Rational#negative?' do
+  assert_predicate(Rational(-2,3), :negative?)
+  assert_predicate(Rational(2,-3), :negative?)
+  assert_not_predicate(Rational(2,3), :negative?)
+  assert_not_predicate(Rational(0), :negative?)
+end