diff -r 000000000000 -r 6474c204b198 uriloader/exthandler/unix/nsGNOMERegistry.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/uriloader/exthandler/unix/nsGNOMERegistry.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,175 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsGNOMERegistry.h"
+#include "nsString.h"
+#include "nsIComponentManager.h"
+#include "nsIFile.h"
+#include "nsMIMEInfoUnix.h"
+#include "nsAutoPtr.h"
+#include "nsIGConfService.h"
+#include "nsIGnomeVFSService.h"
+#include "nsIGIOService.h"
+
+#ifdef MOZ_WIDGET_GTK
+#include <glib.h>
+#include <glib-object.h>
+#endif
+
+/* static */ bool
+nsGNOMERegistry::HandlerExists(const char *aProtocolScheme)
+{
+  nsCOMPtr<nsIGIOService> giovfs = do_GetService(NS_GIOSERVICE_CONTRACTID);
+  nsCOMPtr<nsIGConfService> gconf = do_GetService(NS_GCONFSERVICE_CONTRACTID);
+  if (giovfs) {
+    nsCOMPtr<nsIGIOMimeApp> app;
+    if (NS_FAILED(giovfs->GetAppForURIScheme(nsDependentCString(aProtocolScheme),
+                                             getter_AddRefs(app))))
+      return false;
+    else
+      return true;
+  } else if (gconf) {
+    bool isEnabled;
+    nsAutoCString handler;
+    if (NS_FAILED(gconf->GetAppForProtocol(nsDependentCString(aProtocolScheme), &isEnabled, handler)))
+      return false;
+
+    return isEnabled;
+  }
+
+  return false;
+}
+
+// XXX Check HandlerExists() before calling LoadURL.
+//
+// If there is not a registered handler for the protocol, gnome_url_show()
+// falls back to using gnomevfs modules.  See bug 389632.  We don't want
+// this fallback to happen as we are not sure of the safety of all gnomevfs
+// modules and MIME-default applications.  (gnomevfs should be handled in
+// nsGnomeVFSProtocolHandler.)
+
+/* static */ nsresult
+nsGNOMERegistry::LoadURL(nsIURI *aURL)
+{
+  nsCOMPtr<nsIGIOService> giovfs = do_GetService(NS_GIOSERVICE_CONTRACTID);
+  if (giovfs)
+    return giovfs->ShowURI(aURL);
+
+  nsCOMPtr<nsIGnomeVFSService> gnomevfs = do_GetService(NS_GNOMEVFSSERVICE_CONTRACTID);
+  if (gnomevfs)
+    return gnomevfs->ShowURI(aURL);
+
+  return NS_ERROR_FAILURE;
+}
+
+/* static */ void
+nsGNOMERegistry::GetAppDescForScheme(const nsACString& aScheme,
+                                     nsAString& aDesc)
+{
+  nsCOMPtr<nsIGConfService> gconf = do_GetService(NS_GCONFSERVICE_CONTRACTID);
+  nsCOMPtr<nsIGIOService> giovfs = do_GetService(NS_GIOSERVICE_CONTRACTID);
+  if (!gconf && !giovfs)
+    return;
+
+  nsAutoCString name;
+  if (giovfs) {
+    nsCOMPtr<nsIGIOMimeApp> app;
+    if (NS_FAILED(giovfs->GetAppForURIScheme(aScheme, getter_AddRefs(app))))
+      return;
+
+    app->GetName(name);
+  } else {
+    bool isEnabled;
+    if (NS_FAILED(gconf->GetAppForProtocol(aScheme, &isEnabled, name)))
+      return;
+
+    if (!name.IsEmpty()) {
+      // Try to only provide the executable name, as it is much simpler than with the path and arguments
+      int32_t firstSpace = name.FindChar(' ');
+      if (firstSpace != kNotFound) {
+        name.Truncate(firstSpace);
+        int32_t lastSlash = name.RFindChar('/');
+        if (lastSlash != kNotFound) {
+          name.Cut(0, lastSlash + 1);
+        }
+      }
+    }
+  }
+
+  CopyUTF8toUTF16(name, aDesc);
+}
+
+
+/* static */ already_AddRefed<nsMIMEInfoBase>
+nsGNOMERegistry::GetFromExtension(const nsACString& aFileExt)
+{
+  nsAutoCString mimeType;
+  nsCOMPtr<nsIGIOService> giovfs = do_GetService(NS_GIOSERVICE_CONTRACTID);
+
+  if (giovfs) {
+    // Get the MIME type from the extension, then call GetFromType to
+    // fill in the MIMEInfo.
+    if (NS_FAILED(giovfs->GetMimeTypeFromExtension(aFileExt, mimeType)) ||
+        mimeType.EqualsLiteral("application/octet-stream")) {
+      return nullptr;
+    }
+  } else {
+    /* Fallback to GnomeVFS */
+    nsCOMPtr<nsIGnomeVFSService> gnomevfs = do_GetService(NS_GNOMEVFSSERVICE_CONTRACTID);
+    if (!gnomevfs)
+      return nullptr;
+
+    if (NS_FAILED(gnomevfs->GetMimeTypeFromExtension(aFileExt, mimeType)) ||
+        mimeType.EqualsLiteral("application/octet-stream"))
+      return nullptr;
+  }
+
+  nsRefPtr<nsMIMEInfoBase> mi = GetFromType(mimeType);
+  if (mi) {
+    mi->AppendExtension(aFileExt);
+  }
+
+  return mi.forget();
+}
+
+/* static */ already_AddRefed<nsMIMEInfoBase>
+nsGNOMERegistry::GetFromType(const nsACString& aMIMEType)
+{
+  nsRefPtr<nsMIMEInfoUnix> mimeInfo = new nsMIMEInfoUnix(aMIMEType);
+  NS_ENSURE_TRUE(mimeInfo, nullptr);
+
+  nsAutoCString name;
+  nsAutoCString description;
+
+  nsCOMPtr<nsIGIOService> giovfs = do_GetService(NS_GIOSERVICE_CONTRACTID);
+  if (giovfs) {
+    nsCOMPtr<nsIGIOMimeApp> gioHandlerApp;
+    if (NS_FAILED(giovfs->GetAppForMimeType(aMIMEType, getter_AddRefs(gioHandlerApp))) ||
+        !gioHandlerApp) {
+      return nullptr;
+    }
+    gioHandlerApp->GetName(name);
+    giovfs->GetDescriptionForMimeType(aMIMEType, description);
+  } else {
+    /* Fallback to GnomeVFS*/
+    nsCOMPtr<nsIGnomeVFSService> gnomevfs = do_GetService(NS_GNOMEVFSSERVICE_CONTRACTID);
+    if (!gnomevfs)
+      return nullptr;
+
+    nsCOMPtr<nsIGnomeVFSMimeApp> gnomeHandlerApp;
+    if (NS_FAILED(gnomevfs->GetAppForMimeType(aMIMEType, getter_AddRefs(gnomeHandlerApp))) ||
+        !gnomeHandlerApp) {
+      return nullptr;
+    }
+    gnomeHandlerApp->GetName(name);
+    gnomevfs->GetDescriptionForMimeType(aMIMEType, description);
+  }
+
+  mimeInfo->SetDefaultDescription(NS_ConvertUTF8toUTF16(name));
+  mimeInfo->SetPreferredAction(nsIMIMEInfo::useSystemDefault);
+  mimeInfo->SetDescription(NS_ConvertUTF8toUTF16(description));
+
+  return mimeInfo.forget();
+}