Merge pull request #120 from tenderlove/always-return-ascii-8bit

`to_binary_s` should always return ASCII-8BIT encoded strings

lib/bindata/base.rb

@@ -172,8 +172,7 @@ def num_bytes
     def to_binary_s(&block)
       io = BinData::IO.create_string_io
       write(io, &block)
-      io.rewind
-      io.read
+      io.string
     end
 
     # Returns the hexadecimal string representation of this data object.

test/buffer_test.rb

@@ -52,6 +52,25 @@ class IntBuffer < BinData::Buffer
     obj.to_binary_s.must_equal_binary "\000\003\000\000\000"
   end
 
+  it "returns binary encoded data" do
+    obj = IntBuffer.new(3)
+    obj.to_binary_s.encoding.must_equal Encoding::ASCII_8BIT
+  end
+
+  it "returns binary encoded data despite Encoding.default_internal" do
+    w, $-w = $-w, false
+    before_enc = Encoding.default_internal
+
+    begin
+      Encoding.default_internal = Encoding::UTF_8
+      obj = IntBuffer.new(3)
+      obj.to_binary_s.encoding.must_equal Encoding::ASCII_8BIT
+    ensure
+      Encoding.default_internal = before_enc
+      $-w = w
+    end
+  end
+
   it "has total num_bytes" do
     obj = IntBuffer.new
     assert obj.clear?