Index: apps/metadata/id3tags.c
===================================================================
--- apps/metadata/id3tags.c	(revision 29276)
+++ apps/metadata/id3tags.c	(working copy)
@@ -358,8 +358,7 @@
 
     if ((tag - entry->id3v2buf + desc_len + 2) < bufferpos) {
         /* At least part of the value was read, so we can safely try to
-         * parse it
-         */
+         * parse it */
         value = tag + desc_len + 1;
         value_len = bufferpos - (tag - entry->id3v2buf);
         
@@ -368,8 +367,7 @@
             entry->albumartist = tag;
 #if CONFIG_CODEC == SWCODEC
         } else {
-            value_len = parse_replaygain(tag, value, entry, tag,
-                value_len);
+            value_len = parse_replaygain(tag, value, entry, tag, value_len);
 #endif
         }
     }
@@ -1040,6 +1038,12 @@
 #endif
                 if( tr->ppFunc )
                     bufferpos = tr->ppFunc(entry, tag, bufferpos);
+                    
+                /* Trim. Take into account that multiple string contents will
+                 * only be displayed up to their first null termination. All
+                 * content after this null termination is obsolete and can be
+                 * overwritten. */
+                bufferpos -= (bytesread - strlen(tag));
 
                 /* Seek to the next frame */
                 if(framelen < totframelen)
Index: apps/metadata/mp4.c
===================================================================
--- apps/metadata/mp4.c	(revision 29276)
+++ apps/metadata/mp4.c	(working copy)
@@ -120,11 +120,17 @@
 
     if (bytes_read)
     {
-        (*buffer)[bytes_read] = 0;
-        *dest = *buffer;
-        length = strlen(*buffer) + 1;
-        *buffer_left -= length;
-        *buffer += length;
+        /* Do not overwrite already available metadata. Especially when reading
+         * tags with e.g. multiple genres / artists. This way only the first 
+         * of multiple entries is used, all following are dropped. */
+        if (*dest == NULL)
+        {
+            (*buffer)[bytes_read] = 0;
+            *dest = *buffer;
+            length = strlen(*buffer) + 1;
+            *buffer_left -= length;
+            *buffer += length;
+        }
     }
     else
     {
Index: apps/metadata/metadata_common.c
===================================================================
--- apps/metadata/metadata_common.c	(revision 29276)
+++ apps/metadata/metadata_common.c	(working copy)
@@ -252,19 +252,26 @@
     long len = 0;
     char** p;
 
-    if ((((strcasecmp(name, "track") == 0) && (type == TAGTYPE_APE)))
-        || ((strcasecmp(name, "tracknumber") == 0) && (type == TAGTYPE_VORBIS)))
+    if ((((strcasecmp(name, "track")       == 0) && (type == TAGTYPE_APE   )) ||
+         ((strcasecmp(name, "tracknumber") == 0) && (type == TAGTYPE_VORBIS))) &&
+         (id3->track_string == NULL)
+        )
     {
         id3->tracknum = atoi(value);
         p = &(id3->track_string);
     }
-    else if (strcasecmp(name, "discnumber") == 0 || strcasecmp(name, "disc") == 0)
+    else if ((strcasecmp(name, "discnumber") == 0  || 
+              strcasecmp(name, "disc")       == 0) &&
+             (id3->disc_string == NULL)
+            )
     {
         id3->discnum = atoi(value);
         p = &(id3->disc_string);
     }
-    else if (((strcasecmp(name, "year") == 0) && (type == TAGTYPE_APE))
-        || ((strcasecmp(name, "date") == 0) && (type == TAGTYPE_VORBIS)))
+    else if ((((strcasecmp(name, "year") == 0) && (type == TAGTYPE_APE   )) ||
+              ((strcasecmp(name, "date") == 0) && (type == TAGTYPE_VORBIS))) &&
+             (id3->year_string == NULL)
+            )
     {
         /* Date's can be in any format in Vorbis. However most of them 
          * are in ISO8601 format so if we try and parse the first part
@@ -278,56 +285,58 @@
         }
         p = &(id3->year_string);
     }
-    else if (strcasecmp(name, "title") == 0)
+    else if (strcasecmp(name, "title") == 0 && id3->title == NULL)
     {
         p = &(id3->title);
     }
-    else if (strcasecmp(name, "artist") == 0)
+    else if (strcasecmp(name, "artist") == 0 && id3->artist == NULL)
     {
         p = &(id3->artist);
     }
-    else if (strcasecmp(name, "album") == 0)
+    else if (strcasecmp(name, "album") == 0 && id3->album == NULL)
     {
         p = &(id3->album);
     }
-    else if (strcasecmp(name, "genre") == 0)
+    else if (strcasecmp(name, "genre") == 0 && id3->genre_string == NULL)
     {
         p = &(id3->genre_string);
     }
-    else if (strcasecmp(name, "composer") == 0)
+    else if (strcasecmp(name, "composer") == 0 && id3->composer == NULL)
     {
         p = &(id3->composer);
     }
-    else if (strcasecmp(name, "comment") == 0)
+    else if (strcasecmp(name, "comment") == 0 && id3->comment == NULL)
     {
         p = &(id3->comment);
     }
-    else if (strcasecmp(name, "albumartist") == 0)
+    else if (strcasecmp(name, "albumartist") == 0 && id3->albumartist == NULL)
     {
         p = &(id3->albumartist);
     }
-    else if (strcasecmp(name, "album artist") == 0)
+    else if (strcasecmp(name, "album artist") == 0 && id3->albumartist == NULL)
     {
         p = &(id3->albumartist);
     }
-    else if (strcasecmp(name, "ensemble") == 0)
+    else if (strcasecmp(name, "ensemble") == 0 && id3->albumartist == NULL)
     {
         p = &(id3->albumartist);
     }
-    else if (strcasecmp(name, "grouping") == 0)
+    else if (strcasecmp(name, "grouping") == 0 && id3->grouping == NULL)
     {
         p = &(id3->grouping);
     }
-    else if (strcasecmp(name, "content group") == 0)
+    else if (strcasecmp(name, "content group") == 0 && id3->grouping == NULL)
     {
         p = &(id3->grouping);
     }
-    else if (strcasecmp(name, "contentgroup") == 0) 
+    else if (strcasecmp(name, "contentgroup") == 0 && id3->grouping == NULL) 
     {
         p = &(id3->grouping);
     }
-    else if (strcasecmp(name, "musicbrainz_trackid") == 0
-        || strcasecmp(name, "http://musicbrainz.org") == 0 )
+    else if ((strcasecmp(name, "musicbrainz_trackid")    == 0 || 
+              strcasecmp(name, "http://musicbrainz.org") == 0 ) &&
+             (id3->mb_track_id == NULL)
+            )
     {
         p = &(id3->mb_track_id);
     }