Merge pull request #122 from localshred/bj/backport_string_field_issues

Backport string field encode fixes from 2.8.x

lib/protobuf/field/bytes_field.rb

@@ -18,8 +18,9 @@ def acceptable?(val)
       end
 
       def decode(bytes)
-        bytes.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
-        bytes
+        bytes_to_decode = bytes.dup
+        bytes_to_decode.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
+        bytes_to_decode
       end
 
       def define_setter
@@ -46,11 +47,12 @@ def define_setter
       end
 
       def encode(value)
-        value = value.serialize_to_string if value.is_a?(::Protobuf::Message)
-        value.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
+        value_to_encode = value.dup
+        value_to_encode = value.serialize_to_string if value.is_a?(::Protobuf::Message)
+        value_to_encode.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
 
-        string_size = ::Protobuf::Field::VarintField.encode(value.size)
-        string_size << value
+        string_size = ::Protobuf::Field::VarintField.encode(value_to_encode.size)
+        string_size << value_to_encode
       end
 
       def wire_type

lib/protobuf/field/string_field.rb

@@ -6,17 +6,18 @@ class StringField < BytesField
       ENCODING = 'UTF-8'.freeze
 
       def decode(bytes)
-        bytes.force_encoding(::Protobuf::Field::StringField::ENCODING)
-        bytes
+        bytes_to_decode = bytes.dup
+        bytes_to_decode.force_encoding(::Protobuf::Field::StringField::ENCODING)
+        bytes_to_decode
       end
 
       def encode(value)
-        # TODO: make replace character configurable?
-        value.encode!(::Protobuf::Field::StringField::ENCODING, :invalid => :replace, :undef => :replace, :replace => "")
-        value.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
+        value_to_encode = value.dup
+        value_to_encode.encode!(::Protobuf::Field::StringField::ENCODING, :invalid => :replace, :undef => :replace, :replace => "")
+        value_to_encode.force_encoding(::Protobuf::Field::BytesField::BYTES_ENCODING)
 
-        string_size = ::Protobuf::Field::VarintField.encode(value.size)
-        string_size << value
+        string_size = ::Protobuf::Field::VarintField.encode(value_to_encode.size)
+        string_size << value_to_encode
       end
     end
   end

spec/lib/protobuf/field/string_field_spec.rb

@@ -0,0 +1,46 @@
+# encoding: utf-8
+
+require 'spec_helper'
+
+describe ::Protobuf::Field::StringField do
+
+  describe '#encode' do
+    context 'when a repeated string field contains frozen strings' do
+      it 'does not raise an encoding error' do
+        expect {
+          frozen_strings = [ "foo".freeze, "bar".freeze, "baz".freeze ]
+          ::Test::ResourceFindRequest.new(:name => 'resource', :widgets => frozen_strings).serialize_to_string
+        }.not_to raise_error
+      end
+    end
+
+    context 'when a repeated bytes field contains frozen strings' do
+      it 'does not raise an encoding error' do
+        expect {
+          frozen_strings = [ "foo".freeze, "bar".freeze, "baz".freeze ]
+          ::Test::ResourceFindRequest.new(:name => 'resource', :widget_bytes => frozen_strings).serialize_to_string
+        }.not_to raise_error
+      end
+    end
+
+    it 'does not alter string values after encoding multiple times' do
+      source_string = "foo"
+      proto = ::Test::Resource.new(:name => source_string)
+      proto.serialize_to_string
+      proto.name.should eq source_string
+      proto.serialize_to_string
+      proto.name.should eq source_string
+    end
+
+    it 'does not alter unicode string values after encoding multiple times' do
+      source_string = "¢"
+      proto = ::Test::Resource.new(:name => source_string)
+      proto.serialize_to_string
+      proto.name.should eq source_string
+      proto.serialize_to_string
+      proto.name.should eq source_string
+    end
+  end
+
+
+end