Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/core/array/delete_spec.rb

@@ -0,0 +1,66 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+
+describe "Array#delete" do
+  it "removes elements that are #== to object" do
+    x = mock('delete')
+    def x.==(other) 3 == other end
+
+    a = [1, 2, 3, x, 4, 3, 5, x]
+    a.delete mock('not contained')
+    a.should == [1, 2, 3, x, 4, 3, 5, x]
+
+    a.delete 3
+    a.should == [1, 2, 4, 5]
+  end
+
+  it "calculates equality correctly for reference values" do
+    a = ["foo", "bar", "foo", "quux", "foo"]
+    a.delete "foo"
+    a.should == ["bar","quux"]
+  end
+
+  it "returns object or nil if no elements match object" do
+    [1, 2, 4, 5].delete(1).should == 1
+    [1, 2, 4, 5].delete(3).should == nil
+  end
+
+  it "may be given a block that is executed if no element matches object" do
+    [1].delete(1) {:not_found}.should == 1
+    [].delete('a') {:not_found}.should == :not_found
+  end
+
+  it "returns nil if the array is empty due to a shift" do
+    a = [1]
+    a.shift
+    a.delete(nil).should == nil
+  end
+
+  it "returns nil on a frozen array if a modification does not take place" do
+    [1, 2, 3].freeze.delete(0).should == nil
+  end
+
+  it "raises a RuntimeError on a frozen array" do
+    lambda { [1, 2, 3].freeze.delete(1) }.should raise_error(RuntimeError)
+  end
+
+  it "keeps tainted status" do
+    a = [1, 2]
+    a.taint
+    a.tainted?.should be_true
+    a.delete(2)
+    a.tainted?.should be_true
+    a.delete(1) # now empty
+    a.tainted?.should be_true
+  end
+
+  it "keeps untrusted status" do
+    a = [1, 2]
+    a.untrust
+    a.untrusted?.should be_true
+    a.delete(2)
+    a.untrusted?.should be_true
+    a.delete(1) # now empty
+    a.untrusted?.should be_true
+  end
+end