bug 407116: prevent RSS icon from disappearing when page contains subframes that don't reference RSS feeds; r=mconnor

toolkit/content/widgets/browser.xml

@@ -457,8 +457,10 @@
               this.pageReport = null;
               this.updatePageReport();
             }
-	    if (this.feeds)
-	      this.feeds = null;
+            // Delete the feeds cache if we're hiding the topmost page
+            // (as opposed to one of its iframes).
+            if (this.feeds && event.target == this.contentDocument)
+              this.feeds = null;
             if (!this.docShell || !this.fastFind)
               return;
             var tabBrowser = this.getTabBrowser();