tag: new tag "Mood"

Closes https://github.com/MusicPlayerDaemon/MPD/issues/1435

src/db/plugins/ProxyDatabasePlugin.cxx

@@ -201,6 +201,9 @@ static constexpr struct {
 	{ TAG_MOVEMENT, MPD_TAG_MOVEMENT },
 	{ TAG_MOVEMENTNUMBER, MPD_TAG_MOVEMENTNUMBER },
 	{ TAG_LOCATION, MPD_TAG_LOCATION },
+#endif
+#if LIBMPDCLIENT_CHECK_VERSION(2,21,0)
+	{ TAG_MOOD, MPD_TAG_MOOD },
 #endif
 	{ TAG_NUM_OF_ITEM_TYPES, MPD_TAG_COUNT }
 };

src/tag/Id3Scan.cxx

@@ -60,6 +60,10 @@
 #define ID3_FRAME_LABEL "TPUB"
 #endif
 
+#ifndef ID3_FRAME_MOOD
+#define ID3_FRAME_MOOD "TMOO"
+#endif
+
 gcc_pure
 static Id3String
 tag_id3_getstring(const struct id3_frame *frame, unsigned i) noexcept
@@ -346,6 +350,7 @@ scan_id3_tag(const struct id3_tag *tag, TagHandler &handler) noexcept
 			    handler);
 	tag_id3_import_text(tag, ID3_FRAME_LABEL, TAG_LABEL,
 			    handler);
+	tag_id3_import_text(tag, ID3_FRAME_MOOD, TAG_MOOD, handler);
 
 	tag_id3_import_musicbrainz(tag, handler);
 	tag_id3_import_ufid(tag, handler);

src/tag/Names.c

@@ -30,6 +30,7 @@ const char *const tag_item_names[TAG_NUM_OF_ITEM_TYPES] = {
 	[TAG_TRACK] = "Track",
 	[TAG_NAME] = "Name",
 	[TAG_GENRE] = "Genre",
+	[TAG_MOOD] = "Mood",
 	[TAG_DATE] = "Date",
 	[TAG_ORIGINAL_DATE] = "OriginalDate",
 	[TAG_COMPOSER] = "Composer",

src/tag/Type.h

@@ -45,6 +45,7 @@ enum TagType
 	TAG_TRACK,
 	TAG_NAME,
 	TAG_GENRE,
+	TAG_MOOD,
 	TAG_DATE,
 	TAG_ORIGINAL_DATE,
 	TAG_COMPOSER,