[rygel] core: Don't compare apples and oranges

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 5d387d745677cedb49428031af9839303863c4c4
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Wed Aug 25 16:03:37 2010 +0300

    core: Don't compare apples and oranges
    
    Before comparing two items, first make sure they are of the same type.

 src/rygel/rygel-media-item.vala |    4 ++++
 src/rygel/rygel-music-item.vala |    4 ++++
 src/rygel/rygel-photo-item.vala |    4 ++++
 src/rygel/rygel-video-item.vala |    4 ++++
 4 files changed, 16 insertions(+), 0 deletions(-)
---
diff --git a/src/rygel/rygel-media-item.vala b/src/rygel/rygel-media-item.vala
index 7b7cef2..35e5858 100644
--- a/src/rygel/rygel-media-item.vala
+++ b/src/rygel/rygel-media-item.vala
@@ -127,6 +127,10 @@ public abstract class Rygel.MediaItem : MediaObject {
 
     internal override int compare_by_property (MediaObject media_object,
                                                string      property) {
+        if (!(media_object is MediaItem)) {
+           return 1;
+        }
+
         var item = media_object as MediaItem;
 
         switch (property) {
diff --git a/src/rygel/rygel-music-item.vala b/src/rygel/rygel-music-item.vala
index 3885c13..8e4e6e4 100644
--- a/src/rygel/rygel-music-item.vala
+++ b/src/rygel/rygel-music-item.vala
@@ -74,6 +74,10 @@ public class Rygel.MusicItem : AudioItem {
 
     internal override int compare_by_property (MediaObject media_object,
                                                string      property) {
+        if (!(media_object is MusicItem)) {
+           return 1;
+        }
+
         var item = media_object as MusicItem;
 
         switch (property) {
diff --git a/src/rygel/rygel-photo-item.vala b/src/rygel/rygel-photo-item.vala
index df46cb1..83b1a7b 100644
--- a/src/rygel/rygel-photo-item.vala
+++ b/src/rygel/rygel-photo-item.vala
@@ -43,6 +43,10 @@ public class Rygel.PhotoItem : ImageItem {
 
     internal override int compare_by_property (MediaObject media_object,
                                                string      property) {
+        if (!(media_object is PhotoItem)) {
+           return 1;
+        }
+
         var item = media_object as PhotoItem;
 
         switch (property) {
diff --git a/src/rygel/rygel-video-item.vala b/src/rygel/rygel-video-item.vala
index 4a2ef74..59435cb 100644
--- a/src/rygel/rygel-video-item.vala
+++ b/src/rygel/rygel-video-item.vala
@@ -103,6 +103,10 @@ public class Rygel.VideoItem : AudioItem, VisualItem {
 
     internal override int compare_by_property (MediaObject media_object,
                                                string      property) {
+        if (!(media_object is VideoItem)) {
+           return 1;
+        }
+
         var item = media_object as VideoItem;
 
         switch (property) {