From 9a5d366ce01b7b89e49c36401a351b4be55c4986 Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Wed, 25 Nov 2020 01:39:57 +0100
Subject: [PATCH] Vorbis comment: Turn "YEAR" into "DATE" (unless "DATE"
 exists)

"DATE" is an official field and "YEAR" only an inofficial one but present
in some files. In consistency with MediaInfo and VLC player it is treated
like "DATE" here.
---
 CMakeLists.txt            |  4 ++--
 vorbis/vorbiscomment.cpp  | 11 +++++++++++
 vorbis/vorbiscommentids.h |  4 ++++
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 266b386..ba7d548 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,8 +9,8 @@ set(META_APP_AUTHOR "Martchus")
 set(META_APP_URL "https://github.com/${META_APP_AUTHOR}/${META_PROJECT_NAME}")
 set(META_APP_DESCRIPTION "C++ library for reading and writing MP4 (iTunes), ID3, Vorbis, Opus, FLAC and Matroska tags")
 set(META_VERSION_MAJOR 9)
-set(META_VERSION_MINOR 3)
-set(META_VERSION_PATCH 1)
+set(META_VERSION_MINOR 4)
+set(META_VERSION_PATCH 0)
 set(META_REQUIRED_CPP_UNIT_VERSION 1.14.0)
 set(META_ADD_DEFAULT_CPP_UNIT_TEST_APPLICATION ON)
 
diff --git a/vorbis/vorbiscomment.cpp b/vorbis/vorbiscomment.cpp
index dde26b7..dc66768 100644
--- a/vorbis/vorbiscomment.cpp
+++ b/vorbis/vorbiscomment.cpp
@@ -106,6 +106,7 @@ KnownField VorbisComment::internallyGetKnownField(const IdentifierType &id) cons
          { comment(), KnownField::Comment },
          { cover(), KnownField::Cover },
          { date(), KnownField::RecordDate },
+         { year(), KnownField::RecordDate },
          { title(), KnownField::Title },
          { genre(), KnownField::Genre },
          { trackNumber(), KnownField::TrackPosition },
@@ -181,6 +182,16 @@ template <class StreamType> void VorbisComment::internalParse(StreamType &stream
                 stream.ignore(); // skip framing byte
             }
             m_size = static_cast<std::uint32_t>(static_cast<std::uint64_t>(stream.tellg()) - startOffset);
+            // turn "YEAR" into "DATE" (unless "DATE" exists)
+            // note: "DATE" is an official field and "YEAR" only an inofficial one but present in some files. In consistency with
+            //       MediaInfo and VLC player it is treated like "DATE" here.
+            if (fields().find(VorbisCommentIds::date()) == fields().end()) {
+                const auto [first, end] = fields().equal_range(VorbisCommentIds::year());
+                for (auto i = first; i != end; ++i) {
+                    fields().insert(std::pair(VorbisCommentIds::date(), std::move(i->second)));
+                }
+                fields().erase(first, end);
+            }
         } else {
             diag.emplace_back(DiagLevel::Critical, "Signature is invalid.", context);
             throw InvalidDataException();
diff --git a/vorbis/vorbiscommentids.h b/vorbis/vorbiscommentids.h
index 3a1d66d..1e1a244 100644
--- a/vorbis/vorbiscommentids.h
+++ b/vorbis/vorbiscommentids.h
@@ -143,6 +143,10 @@ constexpr TAG_PARSER_EXPORT const char *date()
 {
     return "DATE";
 }
+constexpr TAG_PARSER_EXPORT const char *year()
+{
+    return "YEAR"; // not mentioned in https://xiph.org/vorbis/doc/v-comment.html but seen in the wild
+}
 constexpr TAG_PARSER_EXPORT const char *location()
 {
     return "LOCATION";