Unconditionally escape unicode newline characters.

Fixes issue 341.

gson/src/main/java/com/google/gson/stream/JsonWriter.java

@@ -431,6 +431,10 @@ public final class JsonWriter implements Closeable {
        * quotation marks except for the characters that must be escaped:
        * quotation mark, reverse solidus, and the control characters
        * (U+0000 through U+001F)."
+       *
+       * We also escape '\u2028' and '\u2029', which JavaScript interprets as
+       * newline characters. This prevents eval() from failing with a syntax
+       * error. http://code.google.com/p/google-gson/issues/detail?id=341
        */
       switch (c) {
       case '"':
@@ -471,6 +475,11 @@ public final class JsonWriter implements Closeable {
         }
         break;
 
+      case '\u2028':
+      case '\u2029':
+        out.write(String.format("\\u%04x", (int) c));
+        break;
+
       default:
         if (c <= 0x1F) {
           out.write(String.format("\\u%04x", (int) c));

gson/src/test/java/com/google/gson/stream/JsonWriterTest.java

@@ -290,6 +290,15 @@ public final class JsonWriterTest extends TestCase {
         + "\"\\u0019\"]", stringWriter.toString());
   }
 
+  public void testUnicodeLineBreaksEscaped() throws IOException {
+    StringWriter stringWriter = new StringWriter();
+    JsonWriter jsonWriter = new JsonWriter(stringWriter);
+    jsonWriter.beginArray();
+    jsonWriter.value("\u2028 \u2029");
+    jsonWriter.endArray();
+    assertEquals("[\"\\u2028 \\u2029\"]", stringWriter.toString());
+  }
+
   public void testEmptyArray() throws IOException {
     StringWriter stringWriter = new StringWriter();
     JsonWriter jsonWriter = new JsonWriter(stringWriter);