diff -r ecd5bb5744dc -r f6b055dd94bc firefox-cross-desktop.patch
--- a/firefox-cross-desktop.patch	Sat Mar 31 09:26:42 2012 +0200
+++ b/firefox-cross-desktop.patch	Sat Mar 31 22:19:28 2012 +0200
@@ -1,14 +1,12 @@
-From: Wolfgang Rosenauer
-NonGnome/KDE integration
-
-References:
-https://bugzilla.novell.com/show_bug.cgi?id=170055
+# HG changeset patch
+# Parent fd2da289a3c15b8c96c248df2710d879793f22c9
+# User Wolfgang Rosenauer <wr@rosenauer.org>
+Bug 526717 - remove non-working "Set as desktop background" from the UI for unsupported desktops
 
 diff --git a/browser/base/content/nsContextMenu.js b/browser/base/content/nsContextMenu.js
 --- a/browser/base/content/nsContextMenu.js
 +++ b/browser/base/content/nsContextMenu.js
-@@ -237,17 +237,19 @@ nsContextMenu.prototype = {
-     this.showItem("context-sep-viewsource", shouldShow);
+@@ -262,17 +262,17 @@ nsContextMenu.prototype = {
  
      // Set as Desktop background depends on whether an image was clicked on,
      // and only works if we have a shell service.
@@ -16,11 +14,9 @@
  #ifdef HAVE_SHELL_SERVICE
      // Only enable Set as Desktop Background if we can get the shell service.
      var shell = getShellService();
--    if (shell)
-+    var env = Components.classes["@mozilla.org/process/environment;1"]
-+                        .getService(Components.interfaces.nsIEnvironment);
-+    if (shell && env.get('DESKTOP_SESSION') == "gnome")
-       haveSetDesktopBackground = true;
+     if (shell)
+-      haveSetDesktopBackground = true;
++      haveSetDesktopBackground = shell.canSetDesktopBackground;
  #endif
      this.showItem("context-setDesktopBackground",
                    haveSetDesktopBackground && this.onLoadedImage);
@@ -28,3 +24,68 @@
      if (haveSetDesktopBackground && this.onLoadedImage) {
        document.getElementById("context-setDesktopBackground")
                .disabled = this.disableSetDesktopBackground();
+     }
+diff --git a/browser/components/shell/public/nsIShellService.idl b/browser/components/shell/public/nsIShellService.idl
+--- a/browser/components/shell/public/nsIShellService.idl
++++ b/browser/components/shell/public/nsIShellService.idl
+@@ -69,16 +69,25 @@ interface nsIShellService : nsISupports
+   /** 
+    * Used to determine whether or not to show a "Set Default Browser"
+    * query dialog. This attribute is true if the application is starting
+    * up and "browser.shell.checkDefaultBrowser" is true, otherwise it
+    * is false.
+    */
+   attribute boolean shouldCheckDefaultBrowser;
+ 
++  /**
++   * Used to determine whether or not to offer "Set as desktop background"
++   * context menu item. Even if shell service is available it is not
++   * guaranteed that it is able to set the background for every desktop
++   * which is especially true for Linux with its many different desktop
++   * environments.
++   */
++  readonly attribute boolean canSetDesktopBackground;
++
+   /** 
+    * Flags for positioning/sizing of the Desktop Background image.
+    */
+   const long BACKGROUND_TILE      = 1;
+   const long BACKGROUND_STRETCH   = 2;
+   const long BACKGROUND_CENTER    = 3;
+   const long BACKGROUND_FILL      = 4;
+   const long BACKGROUND_FIT       = 5;
+diff --git a/browser/components/shell/src/nsGNOMEShellService.cpp b/browser/components/shell/src/nsGNOMEShellService.cpp
+--- a/browser/components/shell/src/nsGNOMEShellService.cpp
++++ b/browser/components/shell/src/nsGNOMEShellService.cpp
+@@ -377,16 +377,31 @@ nsGNOMEShellService::SetShouldCheckDefau
+     pserve->GetBranch("", getter_AddRefs(prefs));
+ 
+   if (prefs)
+     prefs->SetBoolPref(PREF_CHECKDEFAULTBROWSER, aShouldCheck);
+ 
+   return NS_OK;
+ }
+ 
++NS_IMETHODIMP
++nsGNOMEShellService::GetCanSetDesktopBackground(bool* aResult)
++{
++  // setting desktop background is currently only supported
++  // for Gnome or desktops using the same GSettings and GConf keys
++  const char* gnomeSession = getenv("GNOME_DESKTOP_SESSION_ID");
++  if (gnomeSession) {
++    *aResult = true;
++  } else {
++    *aResult = false;
++  }
++
++  return NS_OK;
++}
++
+ static nsresult
+ WriteImage(const nsCString& aPath, imgIContainer* aImage)
+ {
+ #ifndef MOZ_WIDGET_GTK2
+   return NS_ERROR_NOT_AVAILABLE;
+ #else
+   nsCOMPtr<nsIImageToPixbuf> imgToPixbuf =
+     do_GetService("@mozilla.org/widget/image-to-gdk-pixbuf;1");