Fetch cover picture from METADATA_BLOCK_PICTURE tag.

With this patch, covers from Ogg files (for example Vorbis and Opus)
using the recommended METADATA_BLOCK_PICTURE tag will be displayed.

BUG: 328451
FIXED-IN: 2.9
REVIEW: 114406

ChangeLog

@@ -15,6 +15,8 @@ VERSION 2.9-Beta 1
      compilers currently supported by KDE.
 
   BUGFIXES:
+   * Also fetch cover art from xiph-comments with METADATA_BLOCK_PICTURE tag.
+     Patch by Martin Brodbeck <martin@brodbeck-online.de>. (BR 328451)
    * Fix crash on quit when Amarok is in the middle of fadeout. (BR 325723)
    * Prevent shared memory size errors for very large collections. (BR 327812)
    * Fix OpenGL related crash. (BR 327150)

shared/tag_helpers/VorbisCommentTagHelper.cpp

@@ -253,7 +253,10 @@ VorbisCommentTagHelper::embeddedCover() const
     }
     else if( m_tag->fieldListMap().contains( VORBIS_PICTURE_TAG ) )
     {
-        parsePictureBlock( m_tag->fieldListMap()[ VORBIS_PICTURE_TAG ] );
+        QImage resultCover;
+        parsePictureBlock( m_tag->fieldListMap()[ VORBIS_PICTURE_TAG ], &resultCover );
+        if( cover.isNull() && !resultCover.isNull() )
+            cover = resultCover;
     }
     else if( !fieldName( Meta::valHasCover ).isEmpty() )
     {