From a3352fd899c07c30b52855306159fc56a4c92aa3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Lalinsk=C3=BD?= <lalinsky@gmail.com>
Date: Mon, 15 Apr 2013 10:12:02 +0200
Subject: [PATCH] Use the first instance of a MP4 atom (#126)

When a file contains multiple MP4 atoms with the same name, use the first
one. This is consistent with iTunes and other popular software.
---
 taglib/mp4/mp4tag.cpp | 33 +++++++++++++++++++++------------
 taglib/mp4/mp4tag.h   |  2 ++
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/taglib/mp4/mp4tag.cpp b/taglib/mp4/mp4tag.cpp
index 17ab766f..3deb84b3 100644
--- a/taglib/mp4/mp4tag.cpp
+++ b/taglib/mp4/mp4tag.cpp
@@ -159,7 +159,7 @@ MP4::Tag::parseInt(MP4::Atom *atom, TagLib::File *file)
 {
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
-    d->items.insert(atom->name, (int)data[0].toShort());
+    addItem(atom->name, (int)data[0].toShort());
   }
 }
 
@@ -168,7 +168,7 @@ MP4::Tag::parseUInt(MP4::Atom *atom, TagLib::File *file)
 {
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
-    d->items.insert(atom->name, data[0].toUInt());
+    addItem(atom->name, data[0].toUInt());
   }
 }
 
@@ -177,7 +177,7 @@ MP4::Tag::parseLongLong(MP4::Atom *atom, TagLib::File *file)
 {
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
-    d->items.insert(atom->name, data[0].toLongLong());
+    addItem(atom->name, data[0].toLongLong());
   }
 }
 
@@ -186,7 +186,7 @@ MP4::Tag::parseByte(MP4::Atom *atom, TagLib::File *file)
 {
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
-    d->items.insert(atom->name, (uchar)data[0].at(0));
+    addItem(atom->name, (uchar)data[0].at(0));
   }
 }
 
@@ -196,8 +196,8 @@ MP4::Tag::parseGnre(MP4::Atom *atom, TagLib::File *file)
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
     int idx = (int)data[0].toShort();
-    if(!d->items.contains("\251gen") && idx > 0) {
-      d->items.insert("\251gen", StringList(ID3v1::genre(idx - 1)));
+    if(idx > 0) {
+      addItem("\251gen", StringList(ID3v1::genre(idx - 1)));
     }
   }
 }
@@ -209,7 +209,7 @@ MP4::Tag::parseIntPair(MP4::Atom *atom, TagLib::File *file)
   if(data.size()) {
     int a = data[0].mid(2, 2).toShort();
     int b = data[0].mid(4, 2).toShort();
-    d->items.insert(atom->name, MP4::Item(a, b));
+    addItem(atom->name, MP4::Item(a, b));
   }
 }
 
@@ -219,7 +219,7 @@ MP4::Tag::parseBool(MP4::Atom *atom, TagLib::File *file)
   ByteVectorList data = parseData(atom, file);
   if(data.size()) {
     bool value = data[0].size() ? data[0][0] != '\0' : false;
-    d->items.insert(atom->name, value);
+    addItem(atom->name, value);
   }
 }
 
@@ -232,7 +232,7 @@ MP4::Tag::parseText(MP4::Atom *atom, TagLib::File *file, int expectedFlags)
     for(unsigned int i = 0; i < data.size(); i++) {
       value.append(String(data[i], String::UTF8));
     }
-    d->items.insert(atom->name, value);
+    addItem(atom->name, value);
   }
 }
 
@@ -256,7 +256,7 @@ MP4::Tag::parseFreeForm(MP4::Atom *atom, TagLib::File *file)
       }
       Item item(value);
       item.setAtomDataType(type);
-      d->items.insert(name, item);
+      addItem(name, item);
     }
     else {
       ByteVectorList value;
@@ -265,7 +265,7 @@ MP4::Tag::parseFreeForm(MP4::Atom *atom, TagLib::File *file)
       }
       Item item(value);
       item.setAtomDataType(type);
-      d->items.insert(name, item);
+      addItem(name, item);
     }
   }
 }
@@ -294,7 +294,7 @@ MP4::Tag::parseCovr(MP4::Atom *atom, TagLib::File *file)
     pos += length;
   }
   if(value.size() > 0)
-    d->items.insert(atom->name, value);
+    addItem(atom->name, value);
 }
 
 ByteVector
@@ -910,3 +910,12 @@ PropertyMap MP4::Tag::setProperties(const PropertyMap &props)
   return ignoredProps;
 }
 
+void MP4::Tag::addItem(const String &name, const Item &value)
+{
+  if(!d->items.contains(name)) {
+    d->items.insert(name, value);
+  }
+  else {
+    debug("MP4: Ignoring duplicate atom \"" + name + "\"");
+  }
+}
diff --git a/taglib/mp4/mp4tag.h b/taglib/mp4/mp4tag.h
index 0e1d0676..48d71fcb 100644
--- a/taglib/mp4/mp4tag.h
+++ b/taglib/mp4/mp4tag.h
@@ -105,6 +105,8 @@ namespace TagLib {
         void saveNew(TagLib::ByteVector &data);
         void saveExisting(TagLib::ByteVector &data, AtomList &path);
 
+        void addItem(const String &name, const Item &value);
+
         class TagPrivate;
         TagPrivate *d;
     };