1 files changed, 103 insertions, 0 deletions
diff --git a/components/update/app/loaddlls.cpp b/components/update/app/loaddlls.cpp
new file mode 100644
index 000000000..b4291a5df
--- /dev/null
+++ b/components/update/app/loaddlls.cpp
@@ -0,0 +1,103 @@
+/* -*- 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 <windows.h>
+
+// Delayed load libraries are loaded when the first symbol is used.
+// The following ensures that we load the delayed loaded libraries from the
+// system directory.
+struct AutoLoadSystemDependencies
+{
+  AutoLoadSystemDependencies()
+  {
+    // Remove the current directory from the search path for dynamically loaded
+    // DLLs as a precaution.  This call has no effect for delay load DLLs.
+    SetDllDirectory(L"");
+
+    HMODULE module = ::GetModuleHandleW(L"kernel32.dll");
+    if (module) {
+      // SetDefaultDllDirectories is always available on Windows 8 and above. It
+      // is also available on Windows Vista, Windows Server 2008, and
+      // Windows 7 when MS KB2533623 has been applied.
+      decltype(SetDefaultDllDirectories)* setDefaultDllDirectories =
+        (decltype(SetDefaultDllDirectories)*) GetProcAddress(module, "SetDefaultDllDirectories");
+      if (setDefaultDllDirectories) {
+        setDefaultDllDirectories(LOAD_LIBRARY_SEARCH_SYSTEM32);
+        return;
+      }
+    }
+
+    // When SetDefaultDllDirectories is not available, fallback to preloading
+    // dlls. The order that these are loaded does not matter since they are
+    // loaded using the LOAD_WITH_ALTERED_SEARCH_PATH flag.
+#ifdef HAVE_64BIT_BUILD
+    // DLLs for Firefox x64 on Windows 7 (x64).
+    // Note: dwmapi.dll is preloaded since a crash will try to load it from the
+    // application's directory.
+    static LPCWSTR delayDLLs[] = { L"apphelp.dll",
+                                   L"cryptbase.dll",
+                                   L"cryptsp.dll",
+                                   L"dwmapi.dll",
+                                   L"mpr.dll",
+                                   L"ntmarta.dll",
+                                   L"profapi.dll",
+                                   L"propsys.dll",
+                                   L"sspicli.dll",
+                                   L"wsock32.dll" };
+
+#else
+    // DLLs for Firefox x86 on Windows XP through Windows 7 (x86 and x64).
+    // Note: dwmapi.dll is preloaded since a crash will try to load it from the
+    // application's directory.
+    static LPCWSTR delayDLLs[] = { L"apphelp.dll",
+                                   L"crypt32.dll",
+                                   L"cryptbase.dll",
+                                   L"cryptsp.dll",
+                                   L"dwmapi.dll",
+                                   L"mpr.dll",
+                                   L"msasn1.dll",
+                                   L"ntmarta.dll",
+                                   L"profapi.dll",
+                                   L"propsys.dll",
+                                   L"psapi.dll",
+                                   L"secur32.dll",
+                                   L"sspicli.dll",
+                                   L"userenv.dll",
+                                   L"uxtheme.dll",
+                                   L"ws2_32.dll",
+                                   L"ws2help.dll",
+                                   L"wsock32.dll" };
+#endif
+
+    WCHAR systemDirectory[MAX_PATH + 1] = { L'\0' };
+    // If GetSystemDirectory fails we accept that we'll load the DLLs from the
+    // normal search path.
+    GetSystemDirectoryW(systemDirectory, MAX_PATH + 1);
+    size_t systemDirLen = wcslen(systemDirectory);
+
+    // Make the system directory path terminate with a slash
+    if (systemDirectory[systemDirLen - 1] != L'\\' && systemDirLen) {
+      systemDirectory[systemDirLen] = L'\\';
+      ++systemDirLen;
+      // No need to re-null terminate
+    }
+
+    // For each known DLL ensure it is loaded from the system32 directory
+    for (size_t i = 0; i < sizeof(delayDLLs) / sizeof(delayDLLs[0]); ++i) {
+      size_t fileLen = wcslen(delayDLLs[i]);
+      wcsncpy(systemDirectory + systemDirLen, delayDLLs[i],
+              MAX_PATH - systemDirLen);
+      if (systemDirLen + fileLen <= MAX_PATH) {
+        systemDirectory[systemDirLen + fileLen] = L'\0';
+      } else {
+        systemDirectory[MAX_PATH] = L'\0';
+      }
+      LPCWSTR fullModulePath = systemDirectory; // just for code readability
+      // LOAD_WITH_ALTERED_SEARCH_PATH makes a dll look in its own directory for
+      // dependencies and is only available on Win 7 and below.
+      LoadLibraryExW(fullModulePath, nullptr, LOAD_WITH_ALTERED_SEARCH_PATH);
+    }
+  }
+} loadDLLs;