Windows: Prevent event processing during QDesktopServices::openUrl()

The platform implementation uses the Win32 API ShellExecute(),
which may spin an event loop to do COM processing, causing things
like QMetaCallEvent being processed. Run it in a thread
to suppress this.

Pick-to: 5.15
Fixes: QTBUG-85676
Change-Id: I240ca78b41b39ded22e466662ffce8e9b03c10a2
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
This commit is contained in:
Friedemann Kleint 2020-07-27 08:16:14 +02:00
parent 44d4bc6d90
commit ed114b728d

View File

@ -44,6 +44,8 @@
#include <QtCore/qurl.h>
#include <QtCore/qdebug.h>
#include <QtCore/qdir.h>
#include <QtCore/qscopedpointer.h>
#include <QtCore/qthread.h>
#include <QtCore/private/qwinregistry_p.h>
@ -54,15 +56,33 @@ QT_BEGIN_NAMESPACE
enum { debug = 0 };
static quintptr runShellExecute(const wchar_t *path)
{
HINSTANCE result = nullptr;
if (SUCCEEDED(CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE))) {
result = ShellExecute(nullptr, nullptr, path, nullptr, nullptr, SW_SHOWNORMAL);
CoUninitialize();
}
return reinterpret_cast<quintptr>(result);
}
static inline bool shellExecute(const QUrl &url)
{
const QString nativeFilePath = url.isLocalFile() && !url.hasFragment() && !url.hasQuery()
? QDir::toNativeSeparators(url.toLocalFile())
: url.toString(QUrl::FullyEncoded);
const auto result =
reinterpret_cast<quintptr>(ShellExecute(nullptr, nullptr,
reinterpret_cast<const wchar_t *>(nativeFilePath.utf16()),
nullptr, nullptr, SW_SHOWNORMAL));
// Run ShellExecute() in a thread since it may spin the event loop.
// Prevent it from interfering with processing of posted events (QTBUG-85676).
quintptr result = 0;
quintptr *resultPtr = &result;
const auto path = reinterpret_cast<const wchar_t *>(nativeFilePath.utf16());
QScopedPointer<QThread> thread(QThread::create([path, resultPtr]
() { *resultPtr = runShellExecute(path); }));
thread->start();
thread->wait();
// ShellExecute returns a value greater than 32 if successful
if (result <= 32) {
qWarning("ShellExecute '%ls' failed (error %zu).", qUtf16Printable(url.toString()), result);