diff -r 000000000000 -r 6474c204b198 xpcom/glue/AppData.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/AppData.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 8; 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 "mozilla/AppData.h"
+#include "nsXULAppAPI.h"
+#include "nsINIParser.h"
+#include "nsIFile.h"
+#include "nsCRTGlue.h"
+#include "nsAutoPtr.h"
+
+namespace mozilla {
+
+void
+SetAllocatedString(const char *&str, const char *newvalue)
+{
+  NS_Free(const_cast<char*>(str));
+  if (newvalue) {
+    str = NS_strdup(newvalue);
+  }
+  else {
+    str = nullptr;
+  }
+}
+
+void
+SetAllocatedString(const char *&str, const nsACString &newvalue)
+{
+  NS_Free(const_cast<char*>(str));
+  if (newvalue.IsEmpty()) {
+    str = nullptr;
+  }
+  else {
+    str = ToNewCString(newvalue);
+  }
+}
+
+ScopedAppData::ScopedAppData(const nsXREAppData* aAppData)
+{
+  Zero();
+
+  this->size = aAppData->size;
+
+  SetAllocatedString(this->vendor, aAppData->vendor);
+  SetAllocatedString(this->name, aAppData->name);
+  SetAllocatedString(this->version, aAppData->version);
+  SetAllocatedString(this->buildID, aAppData->buildID);
+  SetAllocatedString(this->ID, aAppData->ID);
+  SetAllocatedString(this->copyright, aAppData->copyright);
+  SetAllocatedString(this->profile, aAppData->profile);
+  SetStrongPtr(this->directory, aAppData->directory);
+  this->flags = aAppData->flags;
+
+  if (aAppData->size > offsetof(nsXREAppData, xreDirectory)) {
+    SetStrongPtr(this->xreDirectory, aAppData->xreDirectory);
+    SetAllocatedString(this->minVersion, aAppData->minVersion);
+    SetAllocatedString(this->maxVersion, aAppData->maxVersion);
+  }
+
+  if (aAppData->size > offsetof(nsXREAppData, crashReporterURL)) {
+    SetAllocatedString(this->crashReporterURL, aAppData->crashReporterURL);
+  }
+
+  if (aAppData->size > offsetof(nsXREAppData, UAName)) {
+    SetAllocatedString(this->UAName, aAppData->UAName);
+  }
+}
+
+ScopedAppData::~ScopedAppData()
+{
+  SetAllocatedString(this->vendor, nullptr);
+  SetAllocatedString(this->name, nullptr);
+  SetAllocatedString(this->version, nullptr);
+  SetAllocatedString(this->buildID, nullptr);
+  SetAllocatedString(this->ID, nullptr);
+  SetAllocatedString(this->copyright, nullptr);
+  SetAllocatedString(this->profile, nullptr);
+
+  NS_IF_RELEASE(this->directory);
+
+  SetStrongPtr(this->xreDirectory, (nsIFile*) nullptr);
+  SetAllocatedString(this->minVersion, nullptr);
+  SetAllocatedString(this->maxVersion, nullptr);
+
+  SetAllocatedString(this->crashReporterURL, nullptr);
+  SetAllocatedString(this->UAName, nullptr);
+}
+
+} // namespace mozilla