Fix crash with invalid WAV files (taglib#1163)

With specially crafted WAV files having the "id3 " chunk as the
only valid chunk, when trying to write the tags, the existing
"id3 " chunk is removed, and then vector::front() is called on
the now empty chunks vector.
Now it is checked if the vector is empty to avoid the crash.

taglib/riff/rifffile.cpp

@@ -361,6 +361,9 @@ void RIFF::File::writeChunk(const ByteVector &name, const ByteVector &data,
 
 void RIFF::File::updateGlobalSize()
 {
+ if(d->chunks.empty())
+ return;
+
  const Chunk first = d->chunks.front();
  const Chunk last = d->chunks.back();
  d->size = static_cast<unsigned int>(last.offset + last.size + last.padding - first.offset + 12);

tests/test_wav.cpp

@@ -59,6 +59,7 @@ class TestWAV : public CppUnit::TestFixture
  CPPUNIT_TEST(testStripAndProperties);
  CPPUNIT_TEST(testPCMWithFactChunk);
  CPPUNIT_TEST(testWaveFormatExtensible);
+ CPPUNIT_TEST(testInvalidChunk);
  CPPUNIT_TEST_SUITE_END();
 
 public:
@@ -385,6 +386,23 @@ class TestWAV : public CppUnit::TestFixture
  CPPUNIT_ASSERT_EQUAL(1, f.audioProperties()->format());
  }
 
+ void testInvalidChunk()
+ {
+ ScopedFileCopy copy("invalid-chunk", ".wav");
+
+ {
+ RIFF::WAV::File f(copy.fileName().c_str());
+ CPPUNIT_ASSERT_EQUAL(0, f.audioProperties()->lengthInSeconds());
+ CPPUNIT_ASSERT(f.hasID3v2Tag());
+ f.ID3v2Tag()->setTitle("Title");
+ f.save();
+ }
+ {
+ RIFF::WAV::File f(copy.fileName().c_str());
+ CPPUNIT_ASSERT(!f.hasID3v2Tag());
+ }
+ }
+
 };
 
 CPPUNIT_TEST_SUITE_REGISTRATION(TestWAV);