Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1471 insertions, 0 deletions

diff --git a/widget/windows/nsClipboard.cpp b/widget/windows/nsClipboard.cpp
new file mode 100644
index 0000000000..f2c16343ee
--- /dev/null
+++ b/widget/windows/nsClipboard.cpp
@@ -0,0 +1,1471 @@
+/* -*- 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 "nsClipboard.h"
+
+#include <shlobj.h>
+#include <intshcut.h>
+
+// shellapi.h is needed to build with WIN32_LEAN_AND_MEAN
+#include <shellapi.h>
+
+#include <functional>
+#include <thread>
+#include <chrono>
+
+#ifdef ACCESSIBILITY
+#  include "mozilla/a11y/Compatibility.h"
+#endif
+#include "mozilla/Logging.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_clipboard.h"
+#include "mozilla/StaticPrefs_widget.h"
+#include "mozilla/WindowsVersion.h"
+#include "SpecialSystemDirectory.h"
+
+#include "nsArrayUtils.h"
+#include "nsCOMPtr.h"
+#include "nsComponentManagerUtils.h"
+#include "nsDataObj.h"
+#include "nsString.h"
+#include "nsNativeCharsetUtils.h"
+#include "nsIInputStream.h"
+#include "nsITransferable.h"
+#include "nsXPCOM.h"
+#include "nsReadableUtils.h"
+#include "nsUnicharUtils.h"
+#include "nsPrimitiveHelpers.h"
+#include "nsIWidget.h"
+#include "nsWidgetsCID.h"
+#include "nsCRT.h"
+#include "nsNetUtil.h"
+#include "nsIFileProtocolHandler.h"
+#include "nsEscape.h"
+#include "nsIObserverService.h"
+#include "nsMimeTypes.h"
+#include "imgITools.h"
+#include "imgIContainer.h"
+
+using mozilla::LogLevel;
+
+static mozilla::LazyLogModule gWin32ClipboardLog("nsClipboard");
+
+/* static */
+UINT nsClipboard::GetClipboardFileDescriptorFormatA() {
+  static UINT format = ::RegisterClipboardFormatW(CFSTR_FILEDESCRIPTORA);
+  MOZ_ASSERT(format);
+  return format;
+}
+
+/* static */
+UINT nsClipboard::GetClipboardFileDescriptorFormatW() {
+  static UINT format = ::RegisterClipboardFormatW(CFSTR_FILEDESCRIPTORW);
+  MOZ_ASSERT(format);
+  return format;
+}
+
+/* static */
+UINT nsClipboard::GetHtmlClipboardFormat() {
+  static UINT format = ::RegisterClipboardFormatW(L"HTML Format");
+  return format;
+}
+
+/* static */
+UINT nsClipboard::GetCustomClipboardFormat() {
+  static UINT format =
+      ::RegisterClipboardFormatW(L"application/x-moz-custom-clipdata");
+  return format;
+}
+
+//-------------------------------------------------------------------------
+//
+// nsClipboard constructor
+//
+//-------------------------------------------------------------------------
+nsClipboard::nsClipboard()
+    : nsBaseClipboard(mozilla::dom::ClipboardCapabilities(
+          false /* supportsSelectionClipboard */,
+          false /* supportsFindClipboard */,
+          false /* supportsSelectionCache */)) {
+  mWindow = nullptr;
+
+  // Register for a shutdown notification so that we can flush data
+  // to the OS clipboard.
+  nsCOMPtr<nsIObserverService> observerService =
+      do_GetService("@mozilla.org/observer-service;1");
+  if (observerService) {
+    observerService->AddObserver(this, NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID,
+                                 false);
+  }
+}
+
+//-------------------------------------------------------------------------
+// nsClipboard destructor
+//-------------------------------------------------------------------------
+nsClipboard::~nsClipboard() {}
+
+NS_IMPL_ISUPPORTS_INHERITED(nsClipboard, nsBaseClipboard, nsIObserver)
+
+NS_IMETHODIMP
+nsClipboard::Observe(nsISupports* aSubject, const char* aTopic,
+                     const char16_t* aData) {
+  // This will be called on shutdown.
+  ::OleFlushClipboard();
+  ::CloseClipboard();
+
+  return NS_OK;
+}
+
+//-------------------------------------------------------------------------
+UINT nsClipboard::GetFormat(const char* aMimeStr, bool aMapHTMLMime) {
+  UINT format;
+
+  if (strcmp(aMimeStr, kTextMime) == 0) {
+    format = CF_UNICODETEXT;
+  } else if (strcmp(aMimeStr, kRTFMime) == 0) {
+    format = ::RegisterClipboardFormat(L"Rich Text Format");
+  } else if (strcmp(aMimeStr, kJPEGImageMime) == 0 ||
+             strcmp(aMimeStr, kJPGImageMime) == 0 ||
+             strcmp(aMimeStr, kPNGImageMime) == 0) {
+    format = CF_DIBV5;
+  } else if (strcmp(aMimeStr, kFileMime) == 0 ||
+             strcmp(aMimeStr, kFilePromiseMime) == 0) {
+    format = CF_HDROP;
+  } else if ((strcmp(aMimeStr, kNativeHTMLMime) == 0) ||
+             (aMapHTMLMime && strcmp(aMimeStr, kHTMLMime) == 0)) {
+    format = GetHtmlClipboardFormat();
+  } else if (strcmp(aMimeStr, kCustomTypesMime) == 0) {
+    format = GetCustomClipboardFormat();
+  } else {
+    format = ::RegisterClipboardFormatW(NS_ConvertASCIItoUTF16(aMimeStr).get());
+  }
+
+  return format;
+}
+
+//-------------------------------------------------------------------------
+// static
+nsresult nsClipboard::CreateNativeDataObject(
+    nsITransferable* aTransferable, IDataObject** aDataObj, nsIURI* aUri,
+    MightNeedToFlush* aMightNeedToFlush) {
+  MOZ_ASSERT(aTransferable);
+  if (!aTransferable) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Create our native DataObject that implements the OLE IDataObject interface
+  RefPtr<nsDataObj> dataObj = new nsDataObj(aUri);
+
+  // Now set it up with all the right data flavors & enums
+  nsresult res =
+      SetupNativeDataObject(aTransferable, dataObj, aMightNeedToFlush);
+  if (NS_SUCCEEDED(res)) {
+    dataObj.forget(aDataObj);
+  }
+  return res;
+}
+
+static nsresult StoreValueInDataObject(nsDataObj* aObj,
+                                       LPCWSTR aClipboardFormat, DWORD value) {
+  HGLOBAL hGlobalMemory = ::GlobalAlloc(GMEM_MOVEABLE, sizeof(DWORD));
+  if (!hGlobalMemory) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  DWORD* pdw = (DWORD*)::GlobalLock(hGlobalMemory);
+  *pdw = value;
+  ::GlobalUnlock(hGlobalMemory);
+
+  STGMEDIUM stg;
+  stg.tymed = TYMED_HGLOBAL;
+  stg.pUnkForRelease = nullptr;
+  stg.hGlobal = hGlobalMemory;
+
+  FORMATETC fe;
+  SET_FORMATETC(fe, ::RegisterClipboardFormat(aClipboardFormat), 0,
+                DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+  aObj->SetData(&fe, &stg, TRUE);
+
+  return NS_OK;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::SetupNativeDataObject(
+    nsITransferable* aTransferable, IDataObject* aDataObj,
+    MightNeedToFlush* aMightNeedToFlush) {
+  MOZ_ASSERT(aTransferable);
+  MOZ_ASSERT(aDataObj);
+  if (!aTransferable || !aDataObj) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto* dObj = static_cast<nsDataObj*>(aDataObj);
+  if (aMightNeedToFlush) {
+    *aMightNeedToFlush = MightNeedToFlush::No;
+  }
+
+  // Now give the Transferable to the DataObject
+  // for getting the data out of it
+  dObj->SetTransferable(aTransferable);
+
+  // Get the transferable list of data flavors
+  nsTArray<nsCString> flavors;
+  aTransferable->FlavorsTransferableCanExport(flavors);
+
+  // Walk through flavors that contain data and register them
+  // into the DataObj as supported flavors
+  for (uint32_t i = 0; i < flavors.Length(); i++) {
+    nsCString& flavorStr = flavors[i];
+
+    // When putting data onto the clipboard, we want to maintain kHTMLMime
+    // ("text/html") and not map it to CF_HTML here since this will be done
+    // below.
+    UINT format = GetFormat(flavorStr.get(), false);
+
+    // Now tell the native IDataObject about both our mime type and
+    // the native data format
+    FORMATETC fe;
+    SET_FORMATETC(fe, format, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL);
+    dObj->AddDataFlavor(flavorStr.get(), &fe);
+
+    // Do various things internal to the implementation, like map one
+    // flavor to another or add additional flavors based on what's required
+    // for the win32 impl.
+    if (flavorStr.EqualsLiteral(kTextMime)) {
+      // if we find text/plain, also add CF_TEXT, but we can add it for
+      // text/plain as well.
+      FORMATETC textFE;
+      SET_FORMATETC(textFE, CF_TEXT, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL);
+      dObj->AddDataFlavor(kTextMime, &textFE);
+      if (aMightNeedToFlush) {
+        *aMightNeedToFlush = MightNeedToFlush::Yes;
+      }
+    } else if (flavorStr.EqualsLiteral(kHTMLMime)) {
+      // if we find text/html, also advertise win32's html flavor (which we will
+      // convert on our own in nsDataObj::GetText().
+      FORMATETC htmlFE;
+      SET_FORMATETC(htmlFE, GetHtmlClipboardFormat(), 0, DVASPECT_CONTENT, -1,
+                    TYMED_HGLOBAL);
+      dObj->AddDataFlavor(kHTMLMime, &htmlFE);
+    } else if (flavorStr.EqualsLiteral(kURLMime)) {
+      // if we're a url, in addition to also being text, we need to register
+      // the "file" flavors so that the win32 shell knows to create an internet
+      // shortcut when it sees one of these beasts.
+      FORMATETC shortcutFE;
+      SET_FORMATETC(shortcutFE,
+                    ::RegisterClipboardFormat(CFSTR_FILEDESCRIPTORA), 0,
+                    DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kURLMime, &shortcutFE);
+      SET_FORMATETC(shortcutFE,
+                    ::RegisterClipboardFormat(CFSTR_FILEDESCRIPTORW), 0,
+                    DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kURLMime, &shortcutFE);
+      SET_FORMATETC(shortcutFE, ::RegisterClipboardFormat(CFSTR_FILECONTENTS),
+                    0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kURLMime, &shortcutFE);
+      SET_FORMATETC(shortcutFE, ::RegisterClipboardFormat(CFSTR_INETURLA), 0,
+                    DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kURLMime, &shortcutFE);
+      SET_FORMATETC(shortcutFE, ::RegisterClipboardFormat(CFSTR_INETURLW), 0,
+                    DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kURLMime, &shortcutFE);
+    } else if (flavorStr.EqualsLiteral(kPNGImageMime) ||
+               flavorStr.EqualsLiteral(kJPEGImageMime) ||
+               flavorStr.EqualsLiteral(kJPGImageMime) ||
+               flavorStr.EqualsLiteral(kGIFImageMime) ||
+               flavorStr.EqualsLiteral(kNativeImageMime)) {
+      // if we're an image, register the native bitmap flavor
+      FORMATETC imageFE;
+      // Add DIBv5
+      SET_FORMATETC(imageFE, CF_DIBV5, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(flavorStr.get(), &imageFE);
+      // Add DIBv3
+      SET_FORMATETC(imageFE, CF_DIB, 0, DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(flavorStr.get(), &imageFE);
+    } else if (flavorStr.EqualsLiteral(kFilePromiseMime)) {
+      // if we're a file promise flavor, also register the
+      // CFSTR_PREFERREDDROPEFFECT format.  The data object
+      // returns a value of DROPEFFECTS_MOVE to the drop target
+      // when it asks for the value of this format.  This causes
+      // the file to be moved from the temporary location instead
+      // of being copied.  The right thing to do here is to call
+      // SetData() on the data object and set the value of this format
+      // to DROPEFFECTS_MOVE on this particular data object.  But,
+      // since all the other clipboard formats follow the model of setting
+      // data on the data object only when the drop object calls GetData(),
+      // I am leaving this format's value hard coded in the data object.
+      // We can change this if other consumers of this format get added to this
+      // codebase and they need different values.
+      FORMATETC shortcutFE;
+      SET_FORMATETC(shortcutFE,
+                    ::RegisterClipboardFormat(CFSTR_PREFERREDDROPEFFECT), 0,
+                    DVASPECT_CONTENT, -1, TYMED_HGLOBAL)
+      dObj->AddDataFlavor(kFilePromiseMime, &shortcutFE);
+    }
+  }
+
+  if (!mozilla::StaticPrefs::
+          clipboard_copyPrivateDataToClipboardCloudOrHistory()) {
+    // Let Clipboard know that data is sensitive and must not be copied to
+    // the Cloud Clipboard, Clipboard History and similar.
+    // https://docs.microsoft.com/en-us/windows/win32/dataxchg/clipboard-formats#cloud-clipboard-and-clipboard-history-formats
+    if (aTransferable->GetIsPrivateData()) {
+      nsresult rv =
+          StoreValueInDataObject(dObj, TEXT("CanUploadToCloudClipboard"), 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv =
+          StoreValueInDataObject(dObj, TEXT("CanIncludeInClipboardHistory"), 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = StoreValueInDataObject(
+          dObj, TEXT("ExcludeClipboardContentFromMonitorProcessing"), 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  return NS_OK;
+}
+
+// See methods listed at
+// <https://docs.microsoft.com/en-us/windows/win32/api/objidl/nn-objidl-idataobject#methods>.
+static void IDataObjectMethodResultToString(const HRESULT aHres,
+                                            nsACString& aResult) {
+  switch (aHres) {
+    case E_INVALIDARG:
+      aResult = "E_INVALIDARG";
+      break;
+    case E_UNEXPECTED:
+      aResult = "E_UNEXPECTED";
+      break;
+    case E_OUTOFMEMORY:
+      aResult = "E_OUTOFMEMORY";
+      break;
+    case DV_E_LINDEX:
+      aResult = "DV_E_LINDEX";
+      break;
+    case DV_E_FORMATETC:
+      aResult = "DV_E_FORMATETC";
+      break;
+    case DV_E_TYMED:
+      aResult = "DV_E_TYMED";
+      break;
+    case DV_E_DVASPECT:
+      aResult = "DV_E_DVASPECT";
+      break;
+    case OLE_E_NOTRUNNING:
+      aResult = "OLE_E_NOTRUNNING";
+      break;
+    case STG_E_MEDIUMFULL:
+      aResult = "STG_E_MEDIUMFULL";
+      break;
+    case DV_E_CLIPFORMAT:
+      aResult = "DV_E_CLIPFORMAT";
+      break;
+    case S_OK:
+      aResult = "S_OK";
+      break;
+    default:
+      // Explicit template instantiaton, because otherwise the call is
+      // ambiguous.
+      constexpr int kRadix = 16;
+      aResult = IntToCString<int32_t>(aHres, kRadix);
+      break;
+  }
+}
+
+// See
+// <https://docs.microsoft.com/en-us/windows/win32/api/ole2/nf-ole2-olegetclipboard>.
+static void OleGetClipboardResultToString(const HRESULT aHres,
+                                          nsACString& aResult) {
+  switch (aHres) {
+    case S_OK:
+      aResult = "S_OK";
+      break;
+    case CLIPBRD_E_CANT_OPEN:
+      aResult = "CLIPBRD_E_CANT_OPEN";
+      break;
+    case CLIPBRD_E_CANT_CLOSE:
+      aResult = "CLIPBRD_E_CANT_CLOSE";
+      break;
+    default:
+      // Explicit template instantiaton, because otherwise the call is
+      // ambiguous.
+      constexpr int kRadix = 16;
+      aResult = IntToCString<int32_t>(aHres, kRadix);
+      break;
+  }
+}
+
+// See
+// <https://docs.microsoft.com/en-us/windows/win32/api/ole2/nf-ole2-olegetclipboard>.
+static void LogOleGetClipboardResult(const HRESULT aHres) {
+  if (MOZ_LOG_TEST(gWin32ClipboardLog, LogLevel::Debug)) {
+    nsAutoCString hresString;
+    OleGetClipboardResultToString(aHres, hresString);
+    MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug,
+            ("OleGetClipboard result: %s", hresString.get()));
+  }
+}
+
+// See
+// <https://docs.microsoft.com/en-us/windows/win32/api/ole2/nf-ole2-olesetclipboard>.
+static void OleSetClipboardResultToString(HRESULT aHres, nsACString& aResult) {
+  switch (aHres) {
+    case S_OK:
+      aResult = "S_OK";
+      break;
+    case CLIPBRD_E_CANT_OPEN:
+      aResult = "CLIPBRD_E_CANT_OPEN";
+      break;
+    case CLIPBRD_E_CANT_EMPTY:
+      aResult = "CLIPBRD_E_CANT_EMPTY";
+      break;
+    case CLIPBRD_E_CANT_CLOSE:
+      aResult = "CLIPBRD_E_CANT_CLOSE";
+      break;
+    case CLIPBRD_E_CANT_SET:
+      aResult = "CLIPBRD_E_CANT_SET";
+      break;
+    default:
+      // Explicit template instantiaton, because otherwise the call is
+      // ambiguous.
+      constexpr int kRadix = 16;
+      aResult = IntToCString<int32_t>(aHres, kRadix);
+      break;
+  }
+}
+
+// See
+// <https://docs.microsoft.com/en-us/windows/win32/api/ole2/nf-ole2-olesetclipboard>.
+static void LogOleSetClipboardResult(const HRESULT aHres) {
+  if (MOZ_LOG_TEST(gWin32ClipboardLog, LogLevel::Debug)) {
+    nsAutoCString hresString;
+    OleSetClipboardResultToString(aHres, hresString);
+    MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug,
+            ("OleSetClipboard result: %s", hresString.get()));
+  }
+}
+
+template <typename Function, typename LogFunction, typename... Args>
+static HRESULT RepeatedlyTry(Function aFunction, LogFunction aLogFunction,
+                             Args... aArgs) {
+  // These are magic values based on local testing. They are chosen not higher
+  // to avoid jank (<https://developer.mozilla.org/en-US/docs/Glossary/Jank>).
+  // When changing them, be careful.
+  static constexpr int kNumberOfTries = 3;
+  static constexpr int kDelayInMs = 3;
+
+  HRESULT hres;
+  for (int i = 0; i < kNumberOfTries; ++i) {
+    hres = aFunction(aArgs...);
+    aLogFunction(hres);
+
+    if (hres == S_OK) {
+      break;
+    }
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(kDelayInMs));
+  }
+
+  return hres;
+}
+
+// Other apps can block access to the clipboard. This repeatedly
+// calls `::OleSetClipboard` for a fixed number of times and should be called
+// instead of `::OleSetClipboard`.
+static void RepeatedlyTryOleSetClipboard(IDataObject* aDataObj) {
+  RepeatedlyTry(::OleSetClipboard, LogOleSetClipboardResult, aDataObj);
+}
+
+//-------------------------------------------------------------------------
+NS_IMETHODIMP nsClipboard::SetNativeClipboardData(
+    nsITransferable* aTransferable, nsIClipboardOwner* aOwner,
+    int32_t aWhichClipboard) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  if (aWhichClipboard != kGlobalClipboard) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // make sure we have a good transferable
+  if (!aTransferable) {
+    return NS_ERROR_FAILURE;
+  }
+
+#ifdef ACCESSIBILITY
+  mozilla::a11y::Compatibility::SuppressA11yForClipboardCopy();
+#endif
+
+  RefPtr<IDataObject> dataObj;
+  auto mightNeedToFlush = MightNeedToFlush::No;
+  if (NS_SUCCEEDED(CreateNativeDataObject(aTransferable,
+                                          getter_AddRefs(dataObj), nullptr,
+                                          &mightNeedToFlush))) {
+    RepeatedlyTryOleSetClipboard(dataObj);
+
+    const bool doFlush = [&] {
+      switch (mozilla::StaticPrefs::widget_windows_sync_clipboard_flush()) {
+        case 0:
+          return false;
+        case 1:
+          return true;
+        default:
+          // Bug 1774285: Windows Suggested Actions (introduced in Windows 11
+          // 22H2) walks the entire a11y tree using UIA if something is placed
+          // on the clipboard using delayed rendering. (The OLE clipboard always
+          // uses delayed rendering.) This a11y tree walk causes an unacceptable
+          // hang, particularly when the a11y cache is disabled. We choose the
+          // lesser of the two performance/memory evils here and force immediate
+          // rendering.
+          return mightNeedToFlush == MightNeedToFlush::Yes &&
+                 mozilla::NeedsWindows11SuggestedActionsWorkaround();
+      }
+    }();
+    if (doFlush) {
+      RepeatedlyTry(::OleFlushClipboard, [](HRESULT) {});
+    }
+  } else {
+    // Clear the native clipboard
+    RepeatedlyTryOleSetClipboard(nullptr);
+  }
+
+  return NS_OK;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::GetGlobalData(HGLOBAL aHGBL, void** aData,
+                                    uint32_t* aLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Verbose, ("%s", __FUNCTION__));
+
+  // Allocate a new memory buffer and copy the data from global memory.
+  // Recall that win98 allocates to nearest DWORD boundary. As a safety
+  // precaution, allocate an extra 3 bytes (but don't report them in |aLen|!)
+  // and null them out to ensure that all of our NS_strlen calls will succeed.
+  // NS_strlen operates on char16_t, so we need 3 NUL bytes to ensure it finds
+  // a full NUL char16_t when |*aLen| is odd.
+  nsresult result = NS_ERROR_FAILURE;
+  if (aHGBL != nullptr) {
+    LPSTR lpStr = (LPSTR)GlobalLock(aHGBL);
+    mozilla::CheckedInt<uint32_t> allocSize =
+        mozilla::CheckedInt<uint32_t>(GlobalSize(aHGBL)) + 3;
+    if (!allocSize.isValid()) {
+      return NS_ERROR_INVALID_ARG;
+    }
+    char* data = static_cast<char*>(malloc(allocSize.value()));
+    if (data) {
+      uint32_t size = allocSize.value() - 3;
+      memcpy(data, lpStr, size);
+      // null terminate for safety
+      data[size] = data[size + 1] = data[size + 2] = '\0';
+
+      GlobalUnlock(aHGBL);
+      *aData = data;
+      *aLen = size;
+
+      result = NS_OK;
+    }
+  } else {
+    // We really shouldn't ever get here
+    // but just in case
+    *aData = nullptr;
+    *aLen = 0;
+    LPVOID lpMsgBuf;
+
+    FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, nullptr,
+        GetLastError(),
+        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),  // Default language
+        (LPWSTR)&lpMsgBuf, 0, nullptr);
+
+    // Display the string.
+    MessageBoxW(nullptr, (LPCWSTR)lpMsgBuf, L"GetLastError",
+                MB_OK | MB_ICONINFORMATION);
+
+    // Free the buffer.
+    LocalFree(lpMsgBuf);
+  }
+
+  return result;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::GetNativeDataOffClipboard(nsIWidget* aWidget,
+                                                UINT /*aIndex*/, UINT aFormat,
+                                                void** aData, uint32_t* aLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug,
+          ("%s: overload taking nsIWidget*.", __FUNCTION__));
+
+  HGLOBAL hglb;
+  nsresult result = NS_ERROR_FAILURE;
+
+  HWND nativeWin = nullptr;
+  if (::OpenClipboard(nativeWin)) {
+    hglb = ::GetClipboardData(aFormat);
+    result = GetGlobalData(hglb, aData, aLen);
+    ::CloseClipboard();
+  }
+  return result;
+}
+
+// See methods listed at
+// <https://docs.microsoft.com/en-us/windows/win32/api/objidl/nn-objidl-idataobject#methods>.
+static void LogIDataObjectMethodResult(const HRESULT aHres,
+                                       const nsCString& aMethodName) {
+  if (MOZ_LOG_TEST(gWin32ClipboardLog, LogLevel::Debug)) {
+    nsAutoCString hresString;
+    IDataObjectMethodResultToString(aHres, hresString);
+    MOZ_LOG(
+        gWin32ClipboardLog, LogLevel::Debug,
+        ("IDataObject::%s result: %s", aMethodName.get(), hresString.get()));
+  }
+}
+
+// Other apps can block access to the clipboard. This repeatedly calls
+// `GetData` for a fixed number of times and should be called instead of
+// `GetData`. See
+// <https://docs.microsoft.com/en-us/windows/win32/api/objidl/nf-objidl-idataobject-getdata>.
+// While Microsoft's documentation doesn't include `CLIPBRD_E_CANT_OPEN`
+// explicitly, it allows it implicitly and in local experiments it was indeed
+// returned.
+static HRESULT RepeatedlyTryGetData(IDataObject& aDataObject, LPFORMATETC pFE,
+                                    LPSTGMEDIUM pSTM) {
+  return RepeatedlyTry(
+      [&aDataObject, &pFE, &pSTM]() { return aDataObject.GetData(pFE, pSTM); },
+      std::bind(LogIDataObjectMethodResult, std::placeholders::_1,
+                "GetData"_ns));
+}
+
+//-------------------------------------------------------------------------
+// static
+HRESULT nsClipboard::FillSTGMedium(IDataObject* aDataObject, UINT aFormat,
+                                   LPFORMATETC pFE, LPSTGMEDIUM pSTM,
+                                   DWORD aTymed) {
+  SET_FORMATETC(*pFE, aFormat, 0, DVASPECT_CONTENT, -1, aTymed);
+
+  // Starting by querying for the data to see if we can get it as from global
+  // memory
+  HRESULT hres = S_FALSE;
+  hres = aDataObject->QueryGetData(pFE);
+  LogIDataObjectMethodResult(hres, "QueryGetData"_ns);
+  if (S_OK == hres) {
+    hres = RepeatedlyTryGetData(*aDataObject, pFE, pSTM);
+  }
+  return hres;
+}
+
+//-------------------------------------------------------------------------
+// If aFormat is CF_DIBV5, aMIMEImageFormat must be a type for which we have
+// an image encoder (e.g. image/png).
+// For other values of aFormat, it is OK to pass null for aMIMEImageFormat.
+nsresult nsClipboard::GetNativeDataOffClipboard(IDataObject* aDataObject,
+                                                UINT aIndex, UINT aFormat,
+                                                const char* aMIMEImageFormat,
+                                                void** aData, uint32_t* aLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug,
+          ("%s: overload taking IDataObject*.", __FUNCTION__));
+
+  nsresult result = NS_ERROR_FAILURE;
+  *aData = nullptr;
+  *aLen = 0;
+
+  if (!aDataObject) {
+    return result;
+  }
+
+  UINT format = aFormat;
+  HRESULT hres = S_FALSE;
+
+  // XXX at the moment we only support global memory transfers
+  // It is here where we will add support for native images
+  // and IStream
+  FORMATETC fe;
+  STGMEDIUM stm;
+  hres = FillSTGMedium(aDataObject, format, &fe, &stm, TYMED_HGLOBAL);
+
+  // If the format is CF_HDROP and we haven't found any files we can try looking
+  // for virtual files with FILEDESCRIPTOR.
+  if (FAILED(hres) && format == CF_HDROP) {
+    hres = FillSTGMedium(aDataObject,
+                         nsClipboard::GetClipboardFileDescriptorFormatW(), &fe,
+                         &stm, TYMED_HGLOBAL);
+    if (FAILED(hres)) {
+      hres = FillSTGMedium(aDataObject,
+                           nsClipboard::GetClipboardFileDescriptorFormatA(),
+                           &fe, &stm, TYMED_HGLOBAL);
+    }
+  }
+
+  // Currently this is only handling TYMED_HGLOBAL data
+  // For Text, Dibs, Files, and generic data (like HTML)
+  if (S_OK == hres) {
+    static CLIPFORMAT fileDescriptorFlavorA =
+        ::RegisterClipboardFormat(CFSTR_FILEDESCRIPTORA);
+    static CLIPFORMAT fileDescriptorFlavorW =
+        ::RegisterClipboardFormat(CFSTR_FILEDESCRIPTORW);
+    static CLIPFORMAT fileFlavor =
+        ::RegisterClipboardFormat(CFSTR_FILECONTENTS);
+    static CLIPFORMAT preferredDropEffect =
+        ::RegisterClipboardFormat(CFSTR_PREFERREDDROPEFFECT);
+
+    switch (stm.tymed) {
+      case TYMED_HGLOBAL: {
+        switch (fe.cfFormat) {
+          case CF_TEXT: {
+            // Get the data out of the global data handle. The size we
+            // return should not include the null because the other
+            // platforms don't use nulls, so just return the length we get
+            // back from strlen(), since we know CF_TEXT is null
+            // terminated. Recall that GetGlobalData() returns the size of
+            // the allocated buffer, not the size of the data (on 98, these
+            // are not the same) so we can't use that.
+            uint32_t allocLen = 0;
+            if (NS_SUCCEEDED(GetGlobalData(stm.hGlobal, aData, &allocLen))) {
+              *aLen = strlen(reinterpret_cast<char*>(*aData));
+              result = NS_OK;
+            }
+          } break;
+
+          case CF_UNICODETEXT: {
+            // Get the data out of the global data handle. The size we
+            // return should not include the null because the other
+            // platforms don't use nulls, so just return the length we get
+            // back from strlen(), since we know CF_UNICODETEXT is null
+            // terminated. Recall that GetGlobalData() returns the size of
+            // the allocated buffer, not the size of the data (on 98, these
+            // are not the same) so we can't use that.
+            uint32_t allocLen = 0;
+            if (NS_SUCCEEDED(GetGlobalData(stm.hGlobal, aData, &allocLen))) {
+              *aLen = NS_strlen(reinterpret_cast<char16_t*>(*aData)) * 2;
+              result = NS_OK;
+            }
+          } break;
+
+          case CF_DIBV5:
+            if (aMIMEImageFormat) {
+              uint32_t allocLen = 0;
+              const char* clipboardData;
+              if (NS_SUCCEEDED(GetGlobalData(
+                      stm.hGlobal, (void**)&clipboardData, &allocLen))) {
+                nsCOMPtr<imgIContainer> container;
+                nsCOMPtr<imgITools> imgTools =
+                    do_CreateInstance("@mozilla.org/image/tools;1");
+                result = imgTools->DecodeImageFromBuffer(
+                    clipboardData, allocLen,
+                    nsLiteralCString(IMAGE_BMP_MS_CLIPBOARD),
+                    getter_AddRefs(container));
+                if (NS_FAILED(result)) {
+                  break;
+                }
+
+                nsAutoCString mimeType;
+                if (strcmp(aMIMEImageFormat, kJPGImageMime) == 0) {
+                  mimeType.Assign(IMAGE_JPEG);
+                } else {
+                  mimeType.Assign(aMIMEImageFormat);
+                }
+
+                nsCOMPtr<nsIInputStream> inputStream;
+                result = imgTools->EncodeImage(container, mimeType, u""_ns,
+                                               getter_AddRefs(inputStream));
+                if (NS_FAILED(result)) {
+                  break;
+                }
+
+                if (!inputStream) {
+                  result = NS_ERROR_FAILURE;
+                  break;
+                }
+
+                *aData = inputStream.forget().take();
+                *aLen = sizeof(nsIInputStream*);
+              }
+            }
+            break;
+
+          case CF_HDROP: {
+            // in the case of a file drop, multiple files are stashed within a
+            // single data object. In order to match mozilla's D&D apis, we
+            // just pull out the file at the requested index, pretending as
+            // if there really are multiple drag items.
+            HDROP dropFiles = (HDROP)GlobalLock(stm.hGlobal);
+
+            UINT numFiles = ::DragQueryFileW(dropFiles, 0xFFFFFFFF, nullptr, 0);
+            NS_ASSERTION(numFiles > 0,
+                         "File drop flavor, but no files...hmmmm");
+            NS_ASSERTION(aIndex < numFiles,
+                         "Asked for a file index out of range of list");
+            if (numFiles > 0) {
+              UINT fileNameLen =
+                  ::DragQueryFileW(dropFiles, aIndex, nullptr, 0);
+              wchar_t* buffer = reinterpret_cast<wchar_t*>(
+                  moz_xmalloc((fileNameLen + 1) * sizeof(wchar_t)));
+              ::DragQueryFileW(dropFiles, aIndex, buffer, fileNameLen + 1);
+              *aData = buffer;
+              *aLen = fileNameLen * sizeof(char16_t);
+              result = NS_OK;
+            }
+            GlobalUnlock(stm.hGlobal);
+
+          } break;
+
+          default: {
+            if (fe.cfFormat == fileDescriptorFlavorA ||
+                fe.cfFormat == fileDescriptorFlavorW) {
+              nsAutoString tempPath;
+
+              LPFILEGROUPDESCRIPTOR fgdesc =
+                  static_cast<LPFILEGROUPDESCRIPTOR>(GlobalLock(stm.hGlobal));
+              if (fgdesc) {
+                result = GetTempFilePath(
+                    nsDependentString((fgdesc->fgd)[aIndex].cFileName),
+                    tempPath);
+                GlobalUnlock(stm.hGlobal);
+              }
+              if (NS_FAILED(result)) {
+                break;
+              }
+              result = SaveStorageOrStream(aDataObject, aIndex, tempPath);
+              if (NS_FAILED(result)) {
+                break;
+              }
+              wchar_t* buffer = reinterpret_cast<wchar_t*>(
+                  moz_xmalloc((tempPath.Length() + 1) * sizeof(wchar_t)));
+              wcscpy(buffer, tempPath.get());
+              *aData = buffer;
+              *aLen = tempPath.Length() * sizeof(wchar_t);
+              result = NS_OK;
+            } else if (fe.cfFormat == fileFlavor) {
+              NS_WARNING(
+                  "Mozilla doesn't yet understand how to read this type of "
+                  "file flavor");
+            } else {
+              // Get the data out of the global data handle. The size we
+              // return should not include the null because the other
+              // platforms don't use nulls, so just return the length we get
+              // back from strlen(), since we know CF_UNICODETEXT is null
+              // terminated. Recall that GetGlobalData() returns the size of
+              // the allocated buffer, not the size of the data (on 98, these
+              // are not the same) so we can't use that.
+              //
+              // NOTE: we are assuming that anything that falls into this
+              //        default case is unicode. As we start to get more
+              //        kinds of binary data, this may become an incorrect
+              //        assumption. Stay tuned.
+              uint32_t allocLen = 0;
+              if (NS_SUCCEEDED(GetGlobalData(stm.hGlobal, aData, &allocLen))) {
+                if (fe.cfFormat == GetHtmlClipboardFormat()) {
+                  // CF_HTML is actually UTF8, not unicode, so disregard the
+                  // assumption above. We have to check the header for the
+                  // actual length, and we'll do that in FindPlatformHTML().
+                  // For now, return the allocLen. This case is mostly to
+                  // ensure we don't try to call strlen on the buffer.
+                  *aLen = allocLen;
+                } else if (fe.cfFormat == GetCustomClipboardFormat()) {
+                  // Binary data
+                  *aLen = allocLen;
+                } else if (fe.cfFormat == preferredDropEffect) {
+                  // As per the MSDN doc entitled: "Shell Clipboard Formats"
+                  // CFSTR_PREFERREDDROPEFFECT should return a DWORD
+                  // Reference:
+                  // http://msdn.microsoft.com/en-us/library/bb776902(v=vs.85).aspx
+                  NS_ASSERTION(
+                      allocLen == sizeof(DWORD),
+                      "CFSTR_PREFERREDDROPEFFECT should return a DWORD");
+                  *aLen = allocLen;
+                } else {
+                  *aLen = NS_strlen(reinterpret_cast<char16_t*>(*aData)) *
+                          sizeof(char16_t);
+                }
+                result = NS_OK;
+              }
+            }
+          } break;
+        }  // switch
+      } break;
+
+      case TYMED_GDI: {
+#ifdef DEBUG
+        MOZ_LOG(gWin32ClipboardLog, LogLevel::Info,
+                ("*********************** TYMED_GDI\n"));
+#endif
+      } break;
+
+      default:
+        break;
+    }  // switch
+
+    ReleaseStgMedium(&stm);
+  }
+
+  return result;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::GetDataFromDataObject(IDataObject* aDataObject,
+                                            UINT anIndex, nsIWidget* aWindow,
+                                            nsITransferable* aTransferable) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  // make sure we have a good transferable
+  if (!aTransferable) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsresult res = NS_ERROR_FAILURE;
+
+  // get flavor list that includes all flavors that can be written (including
+  // ones obtained through conversion)
+  nsTArray<nsCString> flavors;
+  res = aTransferable->FlavorsTransferableCanImport(flavors);
+  if (NS_FAILED(res)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Walk through flavors and see which flavor is on the clipboard them on the
+  // native clipboard,
+  for (uint32_t i = 0; i < flavors.Length(); i++) {
+    nsCString& flavorStr = flavors[i];
+    UINT format = GetFormat(flavorStr.get());
+
+    // Try to get the data using the desired flavor. This might fail, but all is
+    // not lost.
+    void* data = nullptr;
+    uint32_t dataLen = 0;
+    bool dataFound = false;
+    if (nullptr != aDataObject) {
+      if (NS_SUCCEEDED(GetNativeDataOffClipboard(aDataObject, anIndex, format,
+                                                 flavorStr.get(), &data,
+                                                 &dataLen))) {
+        dataFound = true;
+      }
+    } else if (nullptr != aWindow) {
+      if (NS_SUCCEEDED(GetNativeDataOffClipboard(aWindow, anIndex, format,
+                                                 &data, &dataLen))) {
+        dataFound = true;
+      }
+    }
+
+    // This is our second chance to try to find some data, having not found it
+    // when directly asking for the flavor. Let's try digging around in other
+    // flavors to help satisfy our craving for data.
+    if (!dataFound) {
+      if (flavorStr.EqualsLiteral(kTextMime)) {
+        dataFound =
+            FindUnicodeFromPlainText(aDataObject, anIndex, &data, &dataLen);
+      } else if (flavorStr.EqualsLiteral(kURLMime)) {
+        // drags from other windows apps expose the native
+        // CFSTR_INETURL{A,W} flavor
+        dataFound = FindURLFromNativeURL(aDataObject, anIndex, &data, &dataLen);
+        if (!dataFound) {
+          dataFound =
+              FindURLFromLocalFile(aDataObject, anIndex, &data, &dataLen);
+        }
+      }
+    }  // if we try one last ditch effort to find our data
+
+    // Hopefully by this point we've found it and can go about our business
+    if (dataFound) {
+      nsCOMPtr<nsISupports> genericDataWrapper;
+      if (flavorStr.EqualsLiteral(kFileMime)) {
+        // we have a file path in |data|. Create an nsLocalFile object.
+        nsDependentString filepath(reinterpret_cast<char16_t*>(data));
+        nsCOMPtr<nsIFile> file;
+        if (NS_SUCCEEDED(
+                NS_NewLocalFile(filepath, false, getter_AddRefs(file)))) {
+          genericDataWrapper = do_QueryInterface(file);
+        }
+        free(data);
+      } else if (flavorStr.EqualsLiteral(kNativeHTMLMime)) {
+        uint32_t dummy;
+        // the editor folks want CF_HTML exactly as it's on the clipboard, no
+        // conversions, no fancy stuff. Pull it off the clipboard, stuff it into
+        // a wrapper and hand it back to them.
+        if (FindPlatformHTML(aDataObject, anIndex, &data, &dummy, &dataLen)) {
+          nsPrimitiveHelpers::CreatePrimitiveForData(
+              flavorStr, data, dataLen, getter_AddRefs(genericDataWrapper));
+        } else {
+          free(data);
+          continue;  // something wrong with this flavor, keep looking for other
+                     // data
+        }
+        free(data);
+      } else if (flavorStr.EqualsLiteral(kHTMLMime)) {
+        uint32_t startOfData = 0;
+        // The JS folks want CF_HTML exactly as it is on the clipboard, but
+        // minus the CF_HTML header index information.
+        // It also needs to be converted to UTF16 and have linebreaks changed.
+        if (FindPlatformHTML(aDataObject, anIndex, &data, &startOfData,
+                             &dataLen)) {
+          dataLen -= startOfData;
+          nsPrimitiveHelpers::CreatePrimitiveForCFHTML(
+              static_cast<char*>(data) + startOfData, &dataLen,
+              getter_AddRefs(genericDataWrapper));
+        } else {
+          free(data);
+          continue;  // something wrong with this flavor, keep looking for other
+                     // data
+        }
+        free(data);
+      } else if (flavorStr.EqualsLiteral(kJPEGImageMime) ||
+                 flavorStr.EqualsLiteral(kJPGImageMime) ||
+                 flavorStr.EqualsLiteral(kPNGImageMime)) {
+        nsIInputStream* imageStream = reinterpret_cast<nsIInputStream*>(data);
+        genericDataWrapper = do_QueryInterface(imageStream);
+        NS_IF_RELEASE(imageStream);
+      } else {
+        // Treat custom types as a string of bytes.
+        if (!flavorStr.EqualsLiteral(kCustomTypesMime)) {
+          bool isRTF = flavorStr.EqualsLiteral(kRTFMime);
+          // we probably have some form of text. The DOM only wants LF, so
+          // convert from Win32 line endings to DOM line endings.
+          int32_t signedLen = static_cast<int32_t>(dataLen);
+          nsLinebreakHelpers::ConvertPlatformToDOMLinebreaks(isRTF, &data,
+                                                             &signedLen);
+          dataLen = signedLen;
+
+          if (isRTF) {
+            // RTF on Windows is known to sometimes deliver an extra null byte.
+            if (dataLen > 0 && static_cast<char*>(data)[dataLen - 1] == '\0') {
+              dataLen--;
+            }
+          }
+        }
+
+        nsPrimitiveHelpers::CreatePrimitiveForData(
+            flavorStr, data, dataLen, getter_AddRefs(genericDataWrapper));
+        free(data);
+      }
+
+      NS_ASSERTION(genericDataWrapper,
+                   "About to put null data into the transferable");
+      aTransferable->SetTransferData(flavorStr.get(), genericDataWrapper);
+      res = NS_OK;
+
+      // we found one, get out of the loop
+      break;
+    }
+  }  // foreach flavor
+
+  return res;
+}
+
+//
+// FindPlatformHTML
+//
+// Someone asked for the OS CF_HTML flavor. We give it back to them exactly
+// as-is.
+//
+bool nsClipboard ::FindPlatformHTML(IDataObject* inDataObject, UINT inIndex,
+                                    void** outData, uint32_t* outStartOfData,
+                                    uint32_t* outDataLen) {
+  // Reference: MSDN doc entitled "HTML Clipboard Format"
+  // http://msdn.microsoft.com/en-us/library/aa767917(VS.85).aspx#unknown_854
+  // CF_HTML is UTF8, not unicode. We also can't rely on it being
+  // null-terminated so we have to check the CF_HTML header for the correct
+  // length. The length we return is the bytecount from the beginning of the
+  // selected data to the end of the selected data, without the null
+  // termination. Because it's UTF8, we're guaranteed the header is ASCII.
+
+  if (!outData || !*outData) {
+    return false;
+  }
+
+  char version[8] = {0};
+  int32_t startOfData = 0;
+  int32_t endOfData = 0;
+  int numFound =
+      sscanf((char*)*outData, "Version:%7s\nStartHTML:%d\nEndHTML:%d", version,
+             &startOfData, &endOfData);
+
+  if (numFound != 3 || startOfData < -1 || endOfData < -1) {
+    return false;
+  }
+
+  // Fixup the start and end markers if they have no context (set to -1)
+  if (startOfData == -1) {
+    startOfData = 0;
+  }
+  if (endOfData == -1) {
+    endOfData = *outDataLen;
+  }
+
+  // Make sure we were passed sane values within our buffer size.
+  // (Note that we've handled all cases of negative endOfData above, so we can
+  // safely cast it to be unsigned here.)
+  if (!endOfData || startOfData >= endOfData ||
+      static_cast<uint32_t>(endOfData) > *outDataLen) {
+    return false;
+  }
+
+  // We want to return the buffer not offset by startOfData because it will be
+  // parsed out later (probably by HTMLEditor::ParseCFHTML) when it is still
+  // in CF_HTML format.
+
+  // We return the byte offset from the start of the data buffer to where the
+  // HTML data starts. The caller might want to extract the HTML only.
+  *outStartOfData = startOfData;
+  *outDataLen = endOfData;
+  return true;
+}
+
+//
+// FindUnicodeFromPlainText
+//
+// Looks for CF_TEXT on the clipboard and converts it into an UTF-16 string
+// if present. Returns this string in outData, and its length in outDataLen.
+// XXXndeakin Windows converts between CF_UNICODE and CF_TEXT automatically
+// so it doesn't seem like this is actually needed.
+//
+bool nsClipboard ::FindUnicodeFromPlainText(IDataObject* inDataObject,
+                                            UINT inIndex, void** outData,
+                                            uint32_t* outDataLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  // We are looking for text/plain and we failed to find it on the clipboard
+  // first, so try again with CF_TEXT. If that is present, convert it to
+  // unicode.
+  nsresult rv = GetNativeDataOffClipboard(inDataObject, inIndex, CF_TEXT,
+                                          nullptr, outData, outDataLen);
+  if (NS_FAILED(rv) || !*outData) {
+    return false;
+  }
+
+  const char* castedText = static_cast<char*>(*outData);
+  nsAutoString tmp;
+  rv = NS_CopyNativeToUnicode(nsDependentCSubstring(castedText, *outDataLen),
+                              tmp);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  // out with the old, in with the new
+  free(*outData);
+  *outData = ToNewUnicode(tmp);
+  *outDataLen = tmp.Length() * sizeof(char16_t);
+
+  return true;
+
+}  // FindUnicodeFromPlainText
+
+//
+// FindURLFromLocalFile
+//
+// we are looking for a URL and couldn't find it, try again with looking for
+// a local file. If we have one, it may either be a normal file or an internet
+// shortcut. In both cases, however, we can get a URL (it will be a file:// url
+// in the local file case).
+//
+bool nsClipboard ::FindURLFromLocalFile(IDataObject* inDataObject, UINT inIndex,
+                                        void** outData, uint32_t* outDataLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  bool dataFound = false;
+
+  nsresult loadResult =
+      GetNativeDataOffClipboard(inDataObject, inIndex, GetFormat(kFileMime),
+                                nullptr, outData, outDataLen);
+  if (NS_SUCCEEDED(loadResult) && *outData) {
+    // we have a file path in |data|. Is it an internet shortcut or a normal
+    // file?
+    const nsDependentString filepath(static_cast<char16_t*>(*outData));
+    nsCOMPtr<nsIFile> file;
+    nsresult rv = NS_NewLocalFile(filepath, true, getter_AddRefs(file));
+    if (NS_FAILED(rv)) {
+      free(*outData);
+      return dataFound;
+    }
+
+    if (IsInternetShortcut(filepath)) {
+      free(*outData);
+      nsAutoCString url;
+      ResolveShortcut(file, url);
+      if (!url.IsEmpty()) {
+        // convert it to unicode and pass it out
+        NS_ConvertUTF8toUTF16 urlString(url);
+        // the internal mozilla URL format, text/x-moz-url, contains
+        // URL\ntitle.  We can guess the title from the file's name.
+        nsAutoString title;
+        file->GetLeafName(title);
+        // We rely on IsInternetShortcut check that file has a .url extension.
+        title.SetLength(title.Length() - 4);
+        if (title.IsEmpty()) {
+          title = urlString;
+        }
+        *outData = ToNewUnicode(urlString + u"\n"_ns + title);
+        *outDataLen =
+            NS_strlen(static_cast<char16_t*>(*outData)) * sizeof(char16_t);
+
+        dataFound = true;
+      }
+    } else {
+      // we have a normal file, use some Necko objects to get our file path
+      nsAutoCString urlSpec;
+      NS_GetURLSpecFromFile(file, urlSpec);
+
+      // convert it to unicode and pass it out
+      free(*outData);
+      *outData = UTF8ToNewUnicode(urlSpec);
+      *outDataLen =
+          NS_strlen(static_cast<char16_t*>(*outData)) * sizeof(char16_t);
+      dataFound = true;
+    }  // else regular file
+  }
+
+  return dataFound;
+}  // FindURLFromLocalFile
+
+//
+// FindURLFromNativeURL
+//
+// we are looking for a URL and couldn't find it using our internal
+// URL flavor, so look for it using the native URL flavor,
+// CF_INETURLSTRW (We don't handle CF_INETURLSTRA currently)
+//
+bool nsClipboard ::FindURLFromNativeURL(IDataObject* inDataObject, UINT inIndex,
+                                        void** outData, uint32_t* outDataLen) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  bool dataFound = false;
+
+  void* tempOutData = nullptr;
+  uint32_t tempDataLen = 0;
+
+  nsresult loadResult = GetNativeDataOffClipboard(
+      inDataObject, inIndex, ::RegisterClipboardFormat(CFSTR_INETURLW), nullptr,
+      &tempOutData, &tempDataLen);
+  if (NS_SUCCEEDED(loadResult) && tempOutData) {
+    nsDependentString urlString(static_cast<char16_t*>(tempOutData));
+    // the internal mozilla URL format, text/x-moz-url, contains
+    // URL\ntitle.  Since we don't actually have a title here,
+    // just repeat the URL to fake it.
+    *outData = ToNewUnicode(urlString + u"\n"_ns + urlString);
+    *outDataLen =
+        NS_strlen(static_cast<char16_t*>(*outData)) * sizeof(char16_t);
+    free(tempOutData);
+    dataFound = true;
+  } else {
+    loadResult = GetNativeDataOffClipboard(
+        inDataObject, inIndex, ::RegisterClipboardFormat(CFSTR_INETURLA),
+        nullptr, &tempOutData, &tempDataLen);
+    if (NS_SUCCEEDED(loadResult) && tempOutData) {
+      // CFSTR_INETURLA is (currently) equal to CFSTR_SHELLURL which is equal to
+      // CF_TEXT which is by definition ANSI encoded.
+      nsCString urlUnescapedA;
+      bool unescaped =
+          NS_UnescapeURL(static_cast<char*>(tempOutData), tempDataLen,
+                         esc_OnlyNonASCII | esc_SkipControl, urlUnescapedA);
+
+      nsString urlString;
+      if (unescaped) {
+        NS_CopyNativeToUnicode(urlUnescapedA, urlString);
+      } else {
+        NS_CopyNativeToUnicode(
+            nsDependentCString(static_cast<char*>(tempOutData), tempDataLen),
+            urlString);
+      }
+
+      // the internal mozilla URL format, text/x-moz-url, contains
+      // URL\ntitle.  Since we don't actually have a title here,
+      // just repeat the URL to fake it.
+      *outData = ToNewUnicode(urlString + u"\n"_ns + urlString);
+      *outDataLen =
+          NS_strlen(static_cast<char16_t*>(*outData)) * sizeof(char16_t);
+      free(tempOutData);
+      dataFound = true;
+    }
+  }
+
+  return dataFound;
+}  // FindURLFromNativeURL
+
+// Other apps can block access to the clipboard. This repeatedly
+// calls `::OleGetClipboard` for a fixed number of times and should be called
+// instead of `::OleGetClipboard`.
+static HRESULT RepeatedlyTryOleGetClipboard(IDataObject** aDataObj) {
+  return RepeatedlyTry(::OleGetClipboard, LogOleGetClipboardResult, aDataObj);
+}
+
+//
+// ResolveShortcut
+//
+void nsClipboard ::ResolveShortcut(nsIFile* aFile, nsACString& outURL) {
+  nsCOMPtr<nsIFileProtocolHandler> fph;
+  nsresult rv = NS_GetFileProtocolHandler(getter_AddRefs(fph));
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  nsCOMPtr<nsIURI> uri;
+  rv = fph->ReadURLFile(aFile, getter_AddRefs(uri));
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  uri->GetSpec(outURL);
+}  // ResolveShortcut
+
+//
+// IsInternetShortcut
+//
+// A file is an Internet Shortcut if it ends with .URL
+//
+bool nsClipboard ::IsInternetShortcut(const nsAString& inFileName) {
+  return StringEndsWith(inFileName, u".url"_ns,
+                        nsCaseInsensitiveStringComparator);
+}  // IsInternetShortcut
+
+//-------------------------------------------------------------------------
+NS_IMETHODIMP
+nsClipboard::GetNativeClipboardData(nsITransferable* aTransferable,
+                                    int32_t aWhichClipboard) {
+  MOZ_LOG(gWin32ClipboardLog, LogLevel::Debug,
+          ("%s aWhichClipboard=%i", __FUNCTION__, aWhichClipboard));
+
+  // make sure we have a good transferable
+  if (!aTransferable || aWhichClipboard != kGlobalClipboard) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult res;
+
+  // This makes sure we can use the OLE functionality for the clipboard
+  IDataObject* dataObj;
+  if (S_OK == RepeatedlyTryOleGetClipboard(&dataObj)) {
+    // Use OLE IDataObject for clipboard operations
+    MOZ_LOG(gWin32ClipboardLog, LogLevel::Verbose,
+            ("%s: use OLE IDataObject.", __FUNCTION__));
+    res = GetDataFromDataObject(dataObj, 0, nullptr, aTransferable);
+    dataObj->Release();
+  } else {
+    // do it the old manual way
+    res = GetDataFromDataObject(nullptr, 0, mWindow, aTransferable);
+  }
+  return res;
+}
+
+NS_IMETHODIMP
+nsClipboard::EmptyClipboard(int32_t aWhichClipboard) {
+  // Some programs such as ZoneAlarm monitor clipboard usage and then open the
+  // clipboard to scan it.  If we i) empty and then ii) set data, then the
+  // 'set data' can sometimes fail with access denied becacuse another program
+  // has the clipboard open.  So to avoid this race condition for OpenClipboard
+  // we do not empty the clipboard when we're setting it.
+  if (aWhichClipboard == kGlobalClipboard && !mEmptyingForSetData) {
+    RepeatedlyTryOleSetClipboard(nullptr);
+  }
+  return nsBaseClipboard::EmptyClipboard(aWhichClipboard);
+}
+
+//-------------------------------------------------------------------------
+NS_IMETHODIMP nsClipboard::HasDataMatchingFlavors(
+    const nsTArray<nsCString>& aFlavorList, int32_t aWhichClipboard,
+    bool* _retval) {
+  *_retval = false;
+  if (aWhichClipboard != kGlobalClipboard) {
+    return NS_OK;
+  }
+
+  for (auto& flavor : aFlavorList) {
+    UINT format = GetFormat(flavor.get());
+    if (IsClipboardFormatAvailable(format)) {
+      *_retval = true;
+      break;
+    }
+  }
+
+  return NS_OK;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::GetTempFilePath(const nsAString& aFileName,
+                                      nsAString& aFilePath) {
+  nsresult result = NS_OK;
+
+  nsCOMPtr<nsIFile> tmpFile;
+  result =
+      GetSpecialSystemDirectory(OS_TemporaryDirectory, getter_AddRefs(tmpFile));
+  NS_ENSURE_SUCCESS(result, result);
+
+  result = tmpFile->Append(aFileName);
+  NS_ENSURE_SUCCESS(result, result);
+
+  result = tmpFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0660);
+  NS_ENSURE_SUCCESS(result, result);
+  result = tmpFile->GetPath(aFilePath);
+
+  return result;
+}
+
+//-------------------------------------------------------------------------
+nsresult nsClipboard::SaveStorageOrStream(IDataObject* aDataObject, UINT aIndex,
+                                          const nsAString& aFileName) {
+  NS_ENSURE_ARG_POINTER(aDataObject);
+
+  FORMATETC fe = {0};
+  SET_FORMATETC(fe, RegisterClipboardFormat(CFSTR_FILECONTENTS), 0,
+                DVASPECT_CONTENT, aIndex, TYMED_ISTORAGE | TYMED_ISTREAM);
+
+  STGMEDIUM stm = {0};
+  HRESULT hres = aDataObject->GetData(&fe, &stm);
+  if (FAILED(hres)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto releaseMediumGuard =
+      mozilla::MakeScopeExit([&] { ReleaseStgMedium(&stm); });
+
+  // We do this check because, even though we *asked* for IStorage or IStream,
+  // it seems that IDataObject providers can just hand us back whatever they
+  // feel like. See Bug 1824644 for a fun example of that!
+  if (stm.tymed != TYMED_ISTORAGE && stm.tymed != TYMED_ISTREAM) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (stm.tymed == TYMED_ISTORAGE) {
+    RefPtr<IStorage> file;
+    hres = StgCreateStorageEx(
+        aFileName.Data(), STGM_CREATE | STGM_READWRITE | STGM_SHARE_EXCLUSIVE,
+        STGFMT_STORAGE, 0, NULL, NULL, IID_IStorage, getter_AddRefs(file));
+    if (FAILED(hres)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    hres = stm.pstg->CopyTo(0, NULL, NULL, file);
+    if (FAILED(hres)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    file->Commit(STGC_DEFAULT);
+
+    return NS_OK;
+  }
+
+  MOZ_ASSERT(stm.tymed == TYMED_ISTREAM);
+
+  HANDLE handle = CreateFile(aFileName.Data(), GENERIC_WRITE, FILE_SHARE_READ,
+                             NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
+  if (handle == INVALID_HANDLE_VALUE) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto fileCloseGuard = mozilla::MakeScopeExit([&] { CloseHandle(handle); });
+
+  const ULONG bufferSize = 4096;
+  char buffer[bufferSize] = {0};
+  ULONG bytesRead = 0;
+  DWORD bytesWritten = 0;
+  while (true) {
+    HRESULT result = stm.pstm->Read(buffer, bufferSize, &bytesRead);
+    if (FAILED(result)) {
+      return NS_ERROR_FAILURE;
+    }
+    if (bytesRead == 0) {
+      break;
+    }
+    if (!WriteFile(handle, buffer, static_cast<DWORD>(bytesRead), &bytesWritten,
+                   NULL)) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+  return NS_OK;
+}