gistfile1.diff

diff --git a/kernel/common/module.rb b/kernel/common/module.rb
index 5f98a67..f4b661a 100644
--- a/kernel/common/module.rb
+++ b/kernel/common/module.rb
@@ -69,6 +69,13 @@ class Module
     class_variable_defined? verify_class_variable_name(name)
   end
 
+  def remove_class_variable(name)
+    Ruby.primitive :module_cvar_remove
+
+    remove_class_variable verify_class_variable_name(name)
+  end
+  private :remove_class_variable
+
   def __class_variables__
     Ruby.primitive :module_class_variables
 
diff --git a/spec/ruby/core/module/class_variable_set_spec.rb b/spec/ruby/core/module/class_variable_set_spec.rb
index 3864935..39700a8 100644
--- a/spec/ruby/core/module/class_variable_set_spec.rb
+++ b/spec/ruby/core/module/class_variable_set_spec.rb
@@ -13,7 +13,7 @@ describe "Module#class_variable_set" do
   end
 
   it "sets the value of a class variable with the given name defined in an included module" do
-    c = Class.new { include ModuleSpecs::MVars }
+    c = Class.new { include ModuleSpecs::MVars.dup }
     c.send(:class_variable_set, "@@mvar", :new_mvar).should == :new_mvar
     c.send(:class_variable_get, "@@mvar").should == :new_mvar
   end
diff --git a/spec/ruby/core/module/fixtures/classes.rb b/spec/ruby/core/module/fixtures/classes.rb
index 36d541d..4fd0e35 100644
--- a/spec/ruby/core/module/fixtures/classes.rb
+++ b/spec/ruby/core/module/fixtures/classes.rb
@@ -7,6 +7,9 @@ module ModuleSpecs
   class SubclassSpec
   end
 
+  class RemoveClassVariable
+  end
+
   module LookupModInMod
     INCS = :ethereal
   end
diff --git a/spec/ruby/core/module/remove_class_variable_spec.rb b/spec/ruby/core/module/remove_class_variable_spec.rb
index 47ee321..95678ac 100644
--- a/spec/ruby/core/module/remove_class_variable_spec.rb
+++ b/spec/ruby/core/module/remove_class_variable_spec.rb
@@ -1,8 +1,45 @@
 require File.expand_path('../../../spec_helper', __FILE__)
 require File.expand_path('../fixtures/classes', __FILE__)
 
-ruby_version_is "1.9" do
-  describe "Module#remove_class_variable" do
-    it "needs to be reviewed for spec completeness"
+describe "Module#remove_class_variable" do
+  it "removes class variable" do
+    m = ModuleSpecs::MVars.dup
+    m.send(:remove_class_variable, :@@mvar)
+    m.class_variable_defined?(:@@mvar).should == false
+  end
+
+  it "returns the value of removing class variable" do
+    m = ModuleSpecs::MVars.dup
+    m.send(:remove_class_variable, :@@mvar).should == :mvar
+  end
+
+  it "raises a NameError when removing class variable declared in included module" do
+    c = ModuleSpecs::RemoveClassVariable.new { include ModuleSpecs::MVars.dup }
+    lambda { c.send(:remove_class_variable, :@@mvar) }.should raise_error(NameError)
+  end
+
+  it "dunno how to name this block" do
+    c = ModuleSpecs::RemoveClassVariable.new { @@mvar = :mvar }
+    lambda { c.send(:remove_class_variable, :@@mvar) }.should raise_error(NameError)
+  end
+
+  it "raises a NameError when passed a symbol with one leading @" do
+    lambda { ModuleSpecs::MVars.send(:remove_class_variable, :@mvar) }.should raise_error(NameError)
+  end
+
+  it "raises a NameError when passed a symbol with no leading @" do
+    lambda { ModuleSpecs::MVars.send(:remove_class_variable, :mvar)  }.should raise_error(NameError)
+  end
+
+  it "raises a NameError when a Fixnum for an uninitialized class variable is given" do
+    lambda { ModuleSpecs::MVars.send(:remove_class_variable, :@@nonexisting_class_variable) }.should raise_error(NameError)
+  end
+
+  ruby_version_is "" ... "1.9" do
+    it "is private" do
+      lambda { ModuleSpecs::MVars.dup.remove_class_variable(:@@mvar) }.should raise_error(NoMethodError)
+    end
   end
 end
diff --git a/vm/builtin/module.cpp b/vm/builtin/module.cpp
index de5fb54..ae04f76 100644
--- a/vm/builtin/module.cpp
+++ b/vm/builtin/module.cpp
@@ -311,7 +311,60 @@ namespace rubinius {
 
     mod_to_query->set_table_ivar(state, name, value);
     return value;
+  }
+
+  Object* Module::cvar_remove(STATE, Symbol* name) {
+    if(!name->is_cvar_p(state)->true_p()) return Primitives::failure();
+
+    Module* mod = this;
+    Module* mod_to_query;
 
+    if(MetaClass* mc = try_as<MetaClass>(mod)) {
+      mod_to_query = as<Module>(mc->attached_instance());
+    } else if(IncludedModule* im = try_as<IncludedModule>(mod)) {
+      mod_to_query = im->module();
+    } else {
+      mod_to_query = mod;
+    }
+
+    if(mod_to_query->table_ivar_defined(state, name)->true_p()) {
+      Object* value = mod_to_query->get_table_ivar(state, name);
+      mod_to_query->del_table_ivar(state, name);
+      return value;
+    }
+
+    std::stringstream ss;
+    mod = this;
+    if(MetaClass* mc = try_as<MetaClass>(mod)) {
+      mod = as<Module>(mc->attached_instance());
+    }
+
+    if (this->cvar_defined(state, name) == Qtrue) {
+      ss << "cannot remove ";
+      ss << name->c_str(state);
+      ss << " for ";
+    } else {
+      ss << "uninitialized class variable ";
+      ss << name->c_str(state);
+      ss << " in module ";
+    }
+
+    if(mod->name()->nil_p()) {
+      if(kind_of<Class>(mod)) {
+        ss << "#<Class>";
+      } else {
+        ss << "#<Module>";
+      }
+    } else {
+      ss << mod->name()->c_str(state);
+    }
+
+    RubyException::raise(
+        Exception::make_exception(state,
+          as<Class>(G(object)->get_const(state, "NameError")),
+          ss.str().c_str()));
+
+    return NULL;
   }
 
   void Module::Info::show(STATE, Object* self, int level) {
diff --git a/vm/builtin/module.hpp b/vm/builtin/module.hpp
index a6cba64..11913f6 100644
--- a/vm/builtin/module.hpp
+++ b/vm/builtin/module.hpp
@@ -61,6 +61,9 @@ namespace rubinius {
     // Ruby.primitive :module_cvar_get_or_set
     Object* cvar_get_or_set(STATE, Symbol* name, Object* val);
 
+    // Ruby.primitive :module_cvar_remove
+    Object* cvar_remove(STATE, Symbol* name);
+
     void setup(STATE);
     void setup(STATE, const char* name, Module* under = NULL);
     void setup(STATE, Symbol* name, Module* under = NULL);