1 files changed, 76 insertions, 0 deletions
diff --git a/widget/windows/UrlmonHeaderOnlyUtils.h b/widget/windows/UrlmonHeaderOnlyUtils.h
new file mode 100644
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+++ b/widget/windows/UrlmonHeaderOnlyUtils.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_UrlmonHeaderOnlyUtils_h
+#define mozilla_UrlmonHeaderOnlyUtils_h
+
+#include "mozilla/ShellHeaderOnlyUtils.h"
+
+namespace mozilla {
+
+/**
+ * We used to validate a uri with SHParseDisplayName to mitigate the Windows
+ * bug (Bug 394974).  However, Bug 1573051 revealed an issue that a fragment,
+ * a string following a hash mark (#), is dropped when we extract a string
+ * from PIDL.  This is the intended behavior of Windows.
+ *
+ * To deal with the fragment issue as well as keeping our mitigation, we
+ * decided to use CreateUri to validate a uri string, but we also keep using
+ * SHParseDisplayName as a pre-check.  This is because there are several
+ * cases where CreateUri succeeds while SHParseDisplayName fails such as
+ * a non-existent file: uri.
+ *
+ * To minimize the impact of introducing CreateUri into the validation logic,
+ * we try to mimic the logic of windows_storage!IUriToPidl (ieframe!IUriToPidl
+ * in Win7) which is executed behind SHParseDisplayName.
+ * What IUriToPidl does is:
+ *   1) If a given uri has a fragment, removes a fragment.
+ *   2) Takes an absolute uri if it's available in the given uri, otherwise
+ *      takes a raw uri.
+ *
+ * As we need to get a full uri including a fragment, this function does 2).
+ */
+inline LauncherResult<_bstr_t> UrlmonValidateUri(const wchar_t* aUri) {
+  LauncherResult<UniqueAbsolutePidl> pidlResult = ShellParseDisplayName(aUri);
+  if (pidlResult.isErr()) {
+    return pidlResult.propagateErr();
+  }
+
+  // The value of |flags| is the same value as used in ieframe!_EnsureIUri in
+  // Win7, which is called behind SHParseDisplayName.  In Win10, on the other
+  // hand, an flag 0x03000000 is also passed to CreateUri, but we don't
+  // specify it because it's undocumented and unknown.
+  constexpr DWORD flags =
+      Uri_CREATE_NO_DECODE_EXTRA_INFO | Uri_CREATE_CANONICALIZE |
+      Uri_CREATE_CRACK_UNKNOWN_SCHEMES | Uri_CREATE_PRE_PROCESS_HTML_URI |
+      Uri_CREATE_IE_SETTINGS;
+  RefPtr<IUri> uri;
+  HRESULT hr;
+  SAFECALL_URLMON_FUNC(CreateUri, aUri, flags, 0, getter_AddRefs(uri));
+  if (FAILED(hr)) {
+    return LAUNCHER_ERROR_FROM_HRESULT(hr);
+  }
+
+  _bstr_t bstrUri;
+
+  hr = uri->GetAbsoluteUri(bstrUri.GetAddress());
+  if (FAILED(hr)) {
+    return LAUNCHER_ERROR_FROM_HRESULT(hr);
+  }
+
+  if (hr == S_FALSE) {
+    hr = uri->GetRawUri(bstrUri.GetAddress());
+    if (FAILED(hr)) {
+      return LAUNCHER_ERROR_FROM_HRESULT(hr);
+    }
+  }
+
+  return bstrUri;
+}
+
+}  // namespace mozilla
+
+#endif  // mozilla_UrlmonHeaderOnlyUtils_h