1 files changed, 12 insertions, 10 deletions
diff --git a/mailnews/extensions/newsblog/content/FeedItem.js b/mailnews/extensions/newsblog/content/FeedItem.js
index c3f9691f8b..25fc8ac300 100644
--- a/mailnews/extensions/newsblog/content/FeedItem.js
+++ b/mailnews/extensions/newsblog/content/FeedItem.js
@@ -452,16 +452,18 @@ function FeedEnclosure(aURL, aContentType, aLength, aTitle)
   this.mTitle = aTitle;
 
   // Generate a fileName from the URL.
-  if (this.mURL)
-  {
-    try
-    {
-      this.mFileName = Services.io.newURI(this.mURL, null, null).
-                                   QueryInterface(Ci.nsIURL).
-                                   fileName;
-    }
-    catch(ex)
-    {
+  if (this.mURL) {
+    try {
+      let uri = Services.io.newURI(this.mURL).QueryInterface(Ci.nsIURL);
+      this.mFileName = uri.fileName;
+      // Determine mimetype from extension if content-type is not present.
+      if (!aContentType) {
+        let contentType = Cc["@mozilla.org/mime;1"]
+                            .getService(Ci.nsIMIMEService)
+                            .getTypeFromExtension(uri.fileExtension);
+        this.mContentType = contentType;
+      }
+    } catch(ex) {
       this.mFileName = this.mURL;
     }
   }