1 files changed, 7 insertions, 2 deletions
diff --git a/spec/ruby/core/string/unpack/m_spec.rb b/spec/ruby/core/string/unpack/m_spec.rb
index 21134514a1..c1c1eea629 100644
--- a/spec/ruby/core/string/unpack/m_spec.rb
+++ b/spec/ruby/core/string/unpack/m_spec.rb
@@ -1,4 +1,4 @@
-# -*- encoding: binary -*-
+# encoding: binary
 require_relative '../../../spec_helper'
 require_relative '../fixtures/classes'
 require_relative 'shared/basic'
@@ -97,6 +97,11 @@ describe "String#unpack with format 'M'" do
       ["=FF=\n",                      ["\xff"]]
     ].should be_computed_by(:unpack, "M")
   end
+
+  it "unpacks incomplete escape sequences as literal characters" do
+    "foo=".unpack("M").should == ["foo="]
+    "foo=4".unpack("M").should == ["foo=4"]
+  end
 end
 
 describe "String#unpack with format 'm'" do
@@ -181,7 +186,7 @@ describe "String#unpack with format 'm'" do
     end
 
     it "raises an ArgumentError for an invalid base64 character" do
-      -> { "dGV%zdA==".unpack("m0") }.should raise_error(ArgumentError)
+      -> { "dGV%zdA==".unpack("m0") }.should.raise(ArgumentError)
     end
   end
 end