[easytag] Support album artist in WavPack tags

[David King <davidk src gnome org>]

commit fa6c9de17173f5234f4072fa615d5ee5e6b7ee52
Author: David King <amigadave amigadave com>
Date:   Sun Dec 21 19:30:33 2014 +0000

    Support album artist in WavPack tags

 src/tags/wavpack_tag.c |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)
---
diff --git a/src/tags/wavpack_tag.c b/src/tags/wavpack_tag.c
index 54c4e8d..b0a8dec 100644
--- a/src/tags/wavpack_tag.c
+++ b/src/tags/wavpack_tag.c
@@ -112,6 +112,16 @@ wavpack_tag_read_file_tag (GFile *file,
     /* Fill the array with \0. */
     strncpy (field, "", MAXLEN);
 
+    /* Album artist. */
+    length = WavpackGetTagItem (wpc, "album artist", field, MAXLEN);
+
+    if (length > 0 && FileTag->album_artist == NULL)
+    {
+        FileTag->album_artist = Try_To_Validate_Utf8_String (field);
+    }
+
+    memset (field, '\0', MAXLEN);
+
     /*
      * Album
      */
@@ -313,6 +323,14 @@ wavpack_tag_write_file_tag (const ET_File *ETFile,
         goto err;
     }
 
+    /* Album artist. */
+    if (FileTag->album_artist
+        && WavpackAppendTagItem (wpc, "album artist", FileTag->album_artist,
+                                 strlen (FileTag->album_artist)) == 0)
+    {
+        goto err;
+    }
+
     /*
      * Album
      */