1 files changed, 32 insertions, 9 deletions
diff --git a/spec/ruby/core/string/unpack/p_spec.rb b/spec/ruby/core/string/unpack/p_spec.rb
index 7c9a502a15..4103730269 100644
--- a/spec/ruby/core/string/unpack/p_spec.rb
+++ b/spec/ruby/core/string/unpack/p_spec.rb
@@ -1,21 +1,44 @@
-require File.expand_path('../../../../spec_helper', __FILE__)
-require File.expand_path('../../fixtures/classes', __FILE__)
-require File.expand_path('../shared/basic', __FILE__)
+require_relative '../../../spec_helper'
+require_relative '../fixtures/classes'
+require_relative 'shared/basic'
+require_relative 'shared/taint'
 
 describe "String#unpack with format 'P'" do
   it_behaves_like :string_unpack_basic, 'P'
+  it_behaves_like :string_unpack_taint, 'P'
 
-  it "returns a random object after consuming a size-of a machine word bytes" do
-    str = "\0" * 1.size
-    str.unpack("P").should be_kind_of(Object)
+  it "round-trips a string through pack and unpack" do
+    ["hello"].pack("P").unpack("P5").should == ["hello"]
+  end
+
+  it "cannot unpack a string except from the same object that created it, or a duplicate of it" do
+    packed = ["hello"].pack("P")
+    packed.unpack("P5").should == ["hello"]
+    packed.dup.unpack("P5").should == ["hello"]
+    -> { packed.to_sym.to_s.unpack("P5") }.should.raise(ArgumentError, /no associated pointer/)
+  end
+
+  it "reads as many characters as specified" do
+    ["hello"].pack("P").unpack("P1").should == ["h"]
+  end
+
+  it "reads only as far as a NUL character" do
+    ["hello"].pack("P").unpack("P10").should == ["hello"]
   end
 end
 
 describe "String#unpack with format 'p'" do
   it_behaves_like :string_unpack_basic, 'p'
+  it_behaves_like :string_unpack_taint, 'p'
+
+  it "round-trips a string through pack and unpack" do
+    ["hello"].pack("p").unpack("p").should == ["hello"]
+  end
 
-  it "returns a random object after consuming a size-of a machine word bytes" do
-    str = "\0" * 1.size
-    str.unpack("p").should be_kind_of(Object)
+  it "cannot unpack a string except from the same object that created it, or a duplicate of it" do
+    packed = ["hello"].pack("p")
+    packed.unpack("p").should == ["hello"]
+    packed.dup.unpack("p").should == ["hello"]
+    -> { packed.to_sym.to_s.unpack("p") }.should.raise(ArgumentError, /no associated pointer/)
   end
 end