gecko-dev/widget/windows/UrlmonHeaderOnlyUtils.h
Toshihito Kikuchi 3b8a3fad8f Bug 1657208 - Dynamic-load urlmon.dll for x86 system. r=freddyb,mhowell
Our data indicates a few users of x86 system hit failure to load urlmon.dll
for unknown reasons.  Since we don't always require urlmon.dll,
we delay-load it, which causes a crash if loading urlmon.dll fails.

A proposed fix is to dynamically load urlmon.dll on x86.

Differential Revision: https://phabricator.services.mozilla.com/D88534
2020-08-28 21:27:22 +00:00

77 lines
2.8 KiB
C++

/* -*- 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