Bug 1709131 - Report whether the current process has a package identity. r=mhowell

Differential Revision: https://phabricator.services.mozilla.com/D114427

Author: agashlin

widget/windows/WinUtils.cpp

@@ -429,6 +429,7 @@ struct CoTaskMemFreePolicy {
 SetThreadDpiAwarenessContextProc WinUtils::sSetThreadDpiAwarenessContext = NULL;
 EnableNonClientDpiScalingProc WinUtils::sEnableNonClientDpiScaling = NULL;
 GetSystemMetricsForDpiProc WinUtils::sGetSystemMetricsForDpi = NULL;
+bool WinUtils::sHasPackageIdentity = false;
 
 /* static */
 void WinUtils::Initialize() {
@@ -461,6 +462,24 @@ void WinUtils::Initialize() {
           user32Dll, "GetSystemMetricsForDpi");
     }
   }
+
+  if (IsWin8OrLater()) {
+    HMODULE kernel32Dll = ::GetModuleHandleW(L"kernel32");
+    if (kernel32Dll) {
+      typedef LONG(WINAPI * GetCurrentPackageIdProc)(UINT32*, BYTE*);
+      GetCurrentPackageIdProc pGetCurrentPackageId =
+          (GetCurrentPackageIdProc)::GetProcAddress(kernel32Dll,
+                                                    "GetCurrentPackageId");
+
+      // If there was any package identity to retrieve, we get
+      // ERROR_INSUFFICIENT_BUFFER. If there had been no package identity it
+      // would instead return APPMODEL_ERROR_NO_PACKAGE.
+      UINT32 packageNameSize = 0;
+      sHasPackageIdentity = pGetCurrentPackageId &&
+                            (pGetCurrentPackageId(&packageNameSize, nullptr) ==
+                             ERROR_INSUFFICIENT_BUFFER);
+    }
+  }
 }
 
 // static

widget/windows/WinUtils.h

@@ -145,6 +145,9 @@ class WinUtils {
   static EnableNonClientDpiScalingProc sEnableNonClientDpiScaling;
   static GetSystemMetricsForDpiProc sGetSystemMetricsForDpi;
 
+  // Set on Initialize().
+  static bool sHasPackageIdentity;
+
  public:
   class AutoSystemDpiAware {
    public:
@@ -218,6 +221,8 @@ class WinUtils {
    */
   static gfx::MarginDouble GetUnwriteableMarginsForDeviceInInches(HDC aHdc);
 
+  static bool HasPackageIdentity() { return sHasPackageIdentity; }
+
   /**
    * Logging helpers that dump output to prlog module 'Widget', console, and
    * OutputDebugString. Note these output in both debug and release builds.

xpcom/base/nsSystemInfo.cpp

@@ -34,6 +34,7 @@
 #  include "nsDirectoryServiceDefs.h"
 #  include "nsDirectoryServiceUtils.h"
 #  include "nsWindowsHelpers.h"
+#  include "WinUtils.h"
 
 #endif
 
@@ -932,6 +933,12 @@ nsresult nsSystemInfo::Init() {
     return rv;
   }
 
+  rv = SetPropertyAsBool(u"hasWinPackageId"_ns,
+                         widget::WinUtils::HasPackageIdentity());
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
 #  ifndef __MINGW32__
   nsAutoString avInfo, antiSpyInfo, firewallInfo;
   if (NS_SUCCEEDED(