From 451d23ca37510ba9dc174a8738806d07747fd690 Mon Sep 17 00:00:00 2001
From: Scott Wheeler <scott@directededge.com>
Date: Mon, 18 May 2015 20:30:19 +0200
Subject: [PATCH] Add isEmpty() to MP4

Closes #457
---
 taglib/mp4/mp4tag.cpp |  5 +++++
 taglib/mp4/mp4tag.h   |  2 ++
 tests/test_mp4.cpp    | 13 +++++++++++++
 3 files changed, 20 insertions(+)

diff --git a/taglib/mp4/mp4tag.cpp b/taglib/mp4/mp4tag.cpp
index 1a2fec7c..08e5f411 100644
--- a/taglib/mp4/mp4tag.cpp
+++ b/taglib/mp4/mp4tag.cpp
@@ -760,6 +760,11 @@ MP4::Tag::setTrack(uint value)
   d->items["trkn"] = MP4::Item(value, 0);
 }
 
+bool MP4::Tag::isEmpty() const
+{
+  return d->items.isEmpty();
+}
+
 MP4::ItemListMap &
 MP4::Tag::itemListMap()
 {
diff --git a/taglib/mp4/mp4tag.h b/taglib/mp4/mp4tag.h
index 48d71fcb..cde68964 100644
--- a/taglib/mp4/mp4tag.h
+++ b/taglib/mp4/mp4tag.h
@@ -65,6 +65,8 @@ namespace TagLib {
         void setYear(uint value);
         void setTrack(uint value);
 
+        virtual bool isEmpty() const;
+
         ItemListMap &itemListMap();
 
         PropertyMap properties() const;
diff --git a/tests/test_mp4.cpp b/tests/test_mp4.cpp
index ac4d4907..9bd2deb7 100644
--- a/tests/test_mp4.cpp
+++ b/tests/test_mp4.cpp
@@ -19,6 +19,7 @@ class TestMP4 : public CppUnit::TestFixture
   CPPUNIT_TEST(testPropertiesALAC);
   CPPUNIT_TEST(testFreeForm);
   CPPUNIT_TEST(testCheckValid);
+  CPPUNIT_TEST(testIsEmpty);
   CPPUNIT_TEST(testUpdateStco);
   CPPUNIT_TEST(testSaveExisingWhenIlstIsLast);
   CPPUNIT_TEST(test64BitAtom);
@@ -62,6 +63,18 @@ public:
     CPPUNIT_ASSERT(f2.isValid());
   }
 
+  void testIsEmpty()
+  {
+    MP4::Tag t1;
+    CPPUNIT_ASSERT(t1.isEmpty());
+    t1.setArtist("Foo");
+    CPPUNIT_ASSERT(!t1.isEmpty());
+
+    MP4::Tag t2;
+    t2.itemListMap()["foo"] = "bar";
+    CPPUNIT_ASSERT(!t2.isEmpty());
+  }
+
   void testUpdateStco()
   {
     ScopedFileCopy copy("no-tags", ".3g2");