From d33d684fab86c0e4e438fcc31ee1451c1f137811 Mon Sep 17 00:00:00 2001
From: Tsuda Kageyu <tsuda.kageyu@gmail.com>
Date: Tue, 24 Mar 2015 10:31:52 +0900
Subject: [PATCH] Discard empty ID3v2 frames instead of adding a dummy null
 byte.

---
 taglib/mpeg/id3v2/id3v2frame.cpp |  3 ---
 taglib/mpeg/id3v2/id3v2tag.cpp   | 11 +++++++++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/taglib/mpeg/id3v2/id3v2frame.cpp b/taglib/mpeg/id3v2/id3v2frame.cpp
index 85e9f66d..bee5375a 100644
--- a/taglib/mpeg/id3v2/id3v2frame.cpp
+++ b/taglib/mpeg/id3v2/id3v2frame.cpp
@@ -193,9 +193,6 @@ void Frame::setText(const String &)
 ByteVector Frame::render() const
 {
   ByteVector fieldData = renderFields();
-  if(fieldData.isEmpty())
-    fieldData = ByteVector("\x00", 1);
-
   d->header->setFrameSize(fieldData.size());
   ByteVector headerData = d->header->render();
 
diff --git a/taglib/mpeg/id3v2/id3v2tag.cpp b/taglib/mpeg/id3v2/id3v2tag.cpp
index 267a45d0..33345407 100644
--- a/taglib/mpeg/id3v2/id3v2tag.cpp
+++ b/taglib/mpeg/id3v2/id3v2tag.cpp
@@ -591,12 +591,19 @@ ByteVector ID3v2::Tag::render(int version) const
   for(FrameList::ConstIterator it = frameList.begin(); it != frameList.end(); it++) {
     (*it)->header()->setVersion(version);
     if((*it)->header()->frameID().size() != 4) {
-      debug("A frame of unsupported or unknown type \'"
+      debug("An ID3v2 frame of unsupported or unknown type \'"
           + String((*it)->header()->frameID()) + "\' has been discarded");
       continue;
     }
-    if(!(*it)->header()->tagAlterPreservation())
+    if(!(*it)->header()->tagAlterPreservation()) {
+      const ByteVector frameData = (*it)->render();
+      if(frameData.size() == Frame::headerSize()) {
+        debug("An empty ID3v2 frame \'"
+          + String((*it)->header()->frameID()) + "\' has been discarded");
+        continue;
+      }
       tagData.append((*it)->render());
+    }
   }
 
   // Compute the amount of padding, and append that to tagData.