Add boxed boolean value() overload.

When calling value() with a Boolean overload resolution would choose value(boolean) which would throw an NPE on null. The other boxed types are all numbers which would resolve to value(Number) and behave correctly.

gson/src/main/java/com/google/gson/internal/bind/JsonTreeWriter.java

@@ -159,6 +159,14 @@ private void put(JsonElement value) {
     return this;
   }
 
+  @Override public JsonWriter value(Boolean value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
+    put(new JsonPrimitive(value));
+    return this;
+  }
+
   @Override public JsonWriter value(double value) throws IOException {
     if (!isLenient() && (Double.isNaN(value) || Double.isInfinite(value))) {
       throw new IllegalArgumentException("JSON forbids NaN and infinities: " + value);

gson/src/main/java/com/google/gson/internal/bind/TypeAdapters.java

@@ -162,10 +162,6 @@ public Boolean read(JsonReader in) throws IOException {
     }
     @Override
     public void write(JsonWriter out, Boolean value) throws IOException {
-      if (value == null) {
-        out.nullValue();
-        return;
-      }
       out.value(value);
     }
   };

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

@@ -468,6 +468,21 @@ public JsonWriter value(boolean value) throws IOException {
     return this;
   }
 
+  /**
+   * Encodes {@code value}.
+   *
+   * @return this writer.
+   */
+  public JsonWriter value(Boolean value) throws IOException {
+    if (value == null) {
+      return nullValue();
+    }
+    writeDeferredName();
+    beforeValue();
+    out.write(value ? "true" : "false");
+    return this;
+  }
+
   /**
    * Encodes {@code value}.
    *

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

@@ -283,6 +283,17 @@ public void testBooleans() throws IOException {
     assertEquals("[true,false]", stringWriter.toString());
   }
 
+  public void testBoxedBooleans() throws IOException {
+    StringWriter stringWriter = new StringWriter();
+    JsonWriter jsonWriter = new JsonWriter(stringWriter);
+    jsonWriter.beginArray();
+    jsonWriter.value((Boolean) true);
+    jsonWriter.value((Boolean) false);
+    jsonWriter.value((Boolean) null);
+    jsonWriter.endArray();
+    assertEquals("[true,false,null]", stringWriter.toString());
+  }
+
   public void testNulls() throws IOException {
     StringWriter stringWriter = new StringWriter();
     JsonWriter jsonWriter = new JsonWriter(stringWriter);