dbus: Fix a bug where we rejected an empty array in PopArrayOfBytes()

An empty array should be allowed. Sometimes, you need to send an
empty array from methods and signals.

BUG=103793
TEST=added a test in dbus_unittests


Review URL: http://codereview.chromium.org/8525012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109561 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 22 insertions, 1 deletions

diff --git a/dbus/message.cc b/dbus/message.cc
index aa9cc55..2750cb1 100644
--- a/dbus/message.cc
+++ b/dbus/message.cc
@@ -755,6 +755,12 @@ bool MessageReader::PopArrayOfBytes(uint8** bytes, size_t* length) {
   MessageReader array_reader(message_);
   if (!PopArray(&array_reader))
       return false;
+  // An empty array is allowed.
+  if (!array_reader.HasMoreData()) {
+    *length = 0;
+    *bytes = NULL;
+    return true;
+  }
   if (!array_reader.CheckDataType(DBUS_TYPE_BYTE))
     return false;
   int int_length = 0;
@@ -762,7 +768,7 @@ bool MessageReader::PopArrayOfBytes(uint8** bytes, size_t* length) {
                                     bytes,
                                     &int_length);
   *length = static_cast<int>(int_length);
-  return bytes != NULL;
+  return true;
 }
 
 bool MessageReader::PopArrayOfStrings(
diff --git a/dbus/message_unittest.cc b/dbus/message_unittest.cc
index 29fe888..9c76b0d 100644
--- a/dbus/message_unittest.cc
+++ b/dbus/message_unittest.cc
@@ -171,6 +171,21 @@ TEST(MessageTest, ArrayOfBytes) {
   EXPECT_EQ(3, output_bytes[2]);
 }
 
+TEST(MessageTest, ArrayOfBytes_Empty) {
+  scoped_ptr<dbus::Response> message(dbus::Response::CreateEmpty());
+  dbus::MessageWriter writer(message.get());
+  std::vector<uint8> bytes;
+  writer.AppendArrayOfBytes(bytes.data(), bytes.size());
+
+  dbus::MessageReader reader(message.get());
+  uint8* output_bytes = NULL;
+  size_t length = 0;
+  ASSERT_TRUE(reader.PopArrayOfBytes(&output_bytes, &length));
+  ASSERT_FALSE(reader.HasMoreData());
+  ASSERT_EQ(0U, length);
+  EXPECT_EQ(NULL, output_bytes);
+}
+
 TEST(MessageTest, ArrayOfStrings) {
   scoped_ptr<dbus::Response> message(dbus::Response::CreateEmpty());
   dbus::MessageWriter writer(message.get());