[rygel] media-export: Try to prevent crash when removing

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit a162076fbba85108a103889479bad9d90c779e7c
Author: Jens Georg <mail jensge org>
Date:   Sat Jul 24 23:29:38 2010 +0300

    media-export: Try to prevent crash when removing
    
    When uri is removed while harvesting, it could lead to a crash. now
    harvesting is cancelled before removing the uri.

 .../rygel-media-export-root-container.vala         |   22 ++++++++++++-------
 1 files changed, 14 insertions(+), 8 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-root-container.vala b/src/plugins/media-export/rygel-media-export-root-container.vala
index f26c618..cdbb394 100644
--- a/src/plugins/media-export/rygel-media-export-root-container.vala
+++ b/src/plugins/media-export/rygel-media-export-root-container.vala
@@ -74,6 +74,7 @@ public class Rygel.MediaExport.RootContainer : Rygel.MediaExport.DBContainer {
         var id = Checksum.compute_for_string (ChecksumType.MD5,
                                               file.get_uri ());
 
+        cancel_harvester (file);
         try {
             this.media_db.remove_by_id (id);
         } catch (Error error) {
@@ -355,6 +356,16 @@ public class Rygel.MediaExport.RootContainer : Rygel.MediaExport.DBContainer {
         this.harvester_trash.remove (harvester);
     }
 
+    private void cancel_harvester (File file) {
+        if (this.harvester.contains (file)) {
+            var harvester = this.harvester[file];
+            harvester.harvested.disconnect (this.on_file_harvested);
+            harvester.cancellable.cancel ();
+            harvester.harvested.connect (this.on_remove_cancelled_harvester);
+            this.harvester_trash.add (harvester);
+        }
+    }
+
     private void harvest (File           file,
                           MediaContainer parent = this,
                           string?        flag   = null) {
@@ -364,14 +375,8 @@ public class Rygel.MediaExport.RootContainer : Rygel.MediaExport.DBContainer {
             return;
         }
 
-        if (this.harvester.contains (file)) {
-            debug (_("Already harvesting; cancelling"));
-            var harvester = this.harvester[file];
-            harvester.harvested.disconnect (this.on_file_harvested);
-            harvester.cancellable.cancel ();
-            harvester.harvested.connect (this.on_remove_cancelled_harvester);
-            this.harvester_trash.add (harvester);
-        }
+        // Cancel currently running harvester
+        cancel_harvester (file);
 
         var harvester = new Harvester (parent,
                                        this.media_db,
@@ -411,6 +416,7 @@ public class Rygel.MediaExport.RootContainer : Rygel.MediaExport.DBContainer {
                 var id = Checksum.compute_for_string (ChecksumType.MD5,
                                                       file.get_uri ());
 
+                cancel_harvester (file);
                 try {
                     // the full object is fetched instead of simply calling
                     // exists because we need the parent to signalize the