Allow deferring QWebEngineCertificateError handling

Introduce defer() method for halting URL load on certificate errors,
and methods for rejecting and ignoring these errors subsequently
in async manner.

[ChangeLog][QtWebEngineWidgets][QWebEngineCertificateError] New
methods for asynchronous decision on certificate error during load.

Fixes: QTBUG-55110
Change-Id: Ib23eb568862ccc360208922a6a581f8e7edc4a7e
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

5 files changed, 114 insertions, 14 deletions

diff --git a/src/webenginewidgets/api/qwebenginecertificateerror.cpp b/src/webenginewidgets/api/qwebenginecertificateerror.cpp
index f04b73615..e8c7a4245 100644
--- a/src/webenginewidgets/api/qwebenginecertificateerror.cpp
+++ b/src/webenginewidgets/api/qwebenginecertificateerror.cpp
@@ -39,6 +39,8 @@
 
 #include "qwebenginecertificateerror.h"
 
+#include "certificate_error_controller.h"
+
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -51,14 +53,37 @@ QT_BEGIN_NAMESPACE
     QWebEnginePage::certificateError().
 */
 
-class QWebEngineCertificateErrorPrivate {
+class QWebEngineCertificateErrorPrivate : public QSharedData {
 public:
     QWebEngineCertificateErrorPrivate(int error, QUrl url, bool overridable, QString errorDescription);
 
+    ~QWebEngineCertificateErrorPrivate() {
+        if (deferred && !answered)
+            rejectCertificate();
+    }
+
+    void resolveError(bool accept) {
+        if (answered)
+            return;
+        answered = true;
+        if (overridable) {
+            if (auto ctl = controller.lock())
+                ctl->accept(accept);
+        }
+    }
+
+    void ignoreCertificateError() { resolveError(true); }
+    void rejectCertificate() { resolveError(false); }
+
     QWebEngineCertificateError::Error error;
     QUrl url;
     bool overridable;
     QString errorDescription;
+
+    bool answered = false, deferred = false;
+    QWeakPointer<CertificateErrorController> controller;
+
+    Q_DISABLE_COPY(QWebEngineCertificateErrorPrivate)
 };
 
 QWebEngineCertificateErrorPrivate::QWebEngineCertificateErrorPrivate(int error, QUrl url, bool overridable, QString errorDescription)
@@ -68,17 +93,30 @@ QWebEngineCertificateErrorPrivate::QWebEngineCertificateErrorPrivate(int error,
     , errorDescription(errorDescription)
 { }
 
-
 /*! \internal
 */
 QWebEngineCertificateError::QWebEngineCertificateError(int error, QUrl url, bool overridable, QString errorDescription)
-    : d_ptr(new QWebEngineCertificateErrorPrivate(error, url, overridable, errorDescription))
+    : d(new QWebEngineCertificateErrorPrivate(error, url, overridable, errorDescription))
 { }
 
 /*! \internal
 */
+QWebEngineCertificateError::QWebEngineCertificateError(const QSharedPointer<CertificateErrorController> &controller)
+    : d(new QWebEngineCertificateErrorPrivate(controller->error(), controller->url(),
+                                              controller->overridable(), controller->errorString()))
+{
+    d->controller = controller;
+}
+
+QWebEngineCertificateError::QWebEngineCertificateError(const QWebEngineCertificateError &other) = default;
+
+QWebEngineCertificateError& QWebEngineCertificateError::operator=(const QWebEngineCertificateError &other) = default;
+
+/*! \internal
+*/
 QWebEngineCertificateError::~QWebEngineCertificateError()
 {
+
 }
 
 /*!
@@ -116,7 +154,6 @@ QWebEngineCertificateError::~QWebEngineCertificateError()
 */
 bool QWebEngineCertificateError::isOverridable() const
 {
-    const Q_D(QWebEngineCertificateError);
     return d->overridable;
 }
 
@@ -127,7 +164,6 @@ bool QWebEngineCertificateError::isOverridable() const
 */
 QUrl QWebEngineCertificateError::url() const
 {
-    const Q_D(QWebEngineCertificateError);
     return d->url;
 }
 
@@ -138,7 +174,6 @@ QUrl QWebEngineCertificateError::url() const
 */
 QWebEngineCertificateError::Error QWebEngineCertificateError::error() const
 {
-    const Q_D(QWebEngineCertificateError);
     return d->error;
 }
 
@@ -149,8 +184,56 @@ QWebEngineCertificateError::Error QWebEngineCertificateError::error() const
 */
 QString QWebEngineCertificateError::errorDescription() const
 {
-    const Q_D(QWebEngineCertificateError);
     return d->errorDescription;
 }
 
+/*!
+    Marks the certificate error for delayed handling.
+
+    This function should be called when there is a need to postpone the decision whether to ignore a
+    certificate error, for example, while waiting for user input. When called, the function pauses the
+    URL request until ignoreCertificateError() or rejectCertificate() is called.
+
+    \note It is only possible to defer overridable certificate errors.
+
+    \sa isOverridable(), deferred()
+*/
+void QWebEngineCertificateError::defer()
+{
+    if (isOverridable())
+        d->deferred = true;
+}
+
+/*!
+    Returns whether the decision for error handling was delayed and the URL load was halted.
+*/
+bool QWebEngineCertificateError::deferred() const
+{
+    return d->deferred;
+}
+
+/*!
+    Ignores the certificate error and continues the loading of the requested URL.
+*/
+void QWebEngineCertificateError::ignoreCertificateError()
+{
+    d->ignoreCertificateError();
+}
+
+/*!
+    Rejects the certificate and aborts the loading of the requested URL.
+*/
+void QWebEngineCertificateError::rejectCertificate()
+{
+    d->rejectCertificate();
+}
+
+/*!
+    Returns \c true if the error was explicitly rejected or accepted.
+*/
+bool QWebEngineCertificateError::answered() const
+{
+    return d->answered;
+}
+
 QT_END_NAMESPACE
diff --git a/src/webenginewidgets/api/qwebenginecertificateerror.h b/src/webenginewidgets/api/qwebenginecertificateerror.h
index 82ac281be..f8805e8a7 100644
--- a/src/webenginewidgets/api/qwebenginecertificateerror.h
+++ b/src/webenginewidgets/api/qwebenginecertificateerror.h
@@ -42,11 +42,12 @@
 
 #include <QtWebEngineWidgets/qtwebenginewidgetsglobal.h>
 
-#include <QtCore/qscopedpointer.h>
+#include <QtCore/qsharedpointer.h>
 #include <QtCore/qurl.h>
 
 QT_BEGIN_NAMESPACE
 
+class CertificateErrorController;
 class QWebEngineCertificateErrorPrivate;
 
 class QWEBENGINEWIDGETS_EXPORT QWebEngineCertificateError {
@@ -78,10 +79,20 @@ public:
     bool isOverridable() const;
     QString errorDescription() const;
 
+    QWebEngineCertificateError(const QWebEngineCertificateError &other);
+    QWebEngineCertificateError& operator=(const QWebEngineCertificateError &other);
+
+    void defer();
+    bool deferred() const;
+
+    void rejectCertificate();
+    void ignoreCertificateError();
+    bool answered() const;
+
 private:
-    Q_DISABLE_COPY(QWebEngineCertificateError)
-    Q_DECLARE_PRIVATE(QWebEngineCertificateError)
-    QScopedPointer<QWebEngineCertificateErrorPrivate> d_ptr;
+    friend class QWebEnginePagePrivate;
+    QWebEngineCertificateError(const QSharedPointer<CertificateErrorController> &controller);
+    QExplicitlySharedDataPointer<QWebEngineCertificateErrorPrivate> d;
 };
 
 QT_END_NAMESPACE
diff --git a/src/webenginewidgets/api/qwebenginepage.cpp b/src/webenginewidgets/api/qwebenginepage.cpp
index c9e9177b7..b22d47916 100644
--- a/src/webenginewidgets/api/qwebenginepage.cpp
+++ b/src/webenginewidgets/api/qwebenginepage.cpp
@@ -294,6 +294,7 @@ void QWebEnginePagePrivate::loadStarted(const QUrl &provisionalUrl, bool isError
         return;
 
     isLoading = true;
+    m_certificateErrorControllers.clear();
     QTimer::singleShot(0, q, &QWebEnginePage::loadStarted);
 }
 
@@ -1715,10 +1716,11 @@ void QWebEnginePagePrivate::allowCertificateError(const QSharedPointer<Certifica
     Q_Q(QWebEnginePage);
     bool accepted = false;
 
-    QWebEngineCertificateError error(controller->error(), controller->url(), controller->overridable() && !controller->strictEnforcement(), controller->errorString());
+    QWebEngineCertificateError error(controller);
     accepted = q->certificateError(error);
-
-    if (error.isOverridable())
+    if (error.deferred() && !error.answered())
+        m_certificateErrorControllers.append(controller);
+    else if (!error.answered() && error.isOverridable())
         controller->accept(accepted);
 }
 
diff --git a/src/webenginewidgets/api/qwebenginepage_p.h b/src/webenginewidgets/api/qwebenginepage_p.h
index fae97b9fa..2843f69c4 100644
--- a/src/webenginewidgets/api/qwebenginepage_p.h
+++ b/src/webenginewidgets/api/qwebenginepage_p.h
@@ -210,6 +210,8 @@ public:
 #if QT_CONFIG(webengine_printing_and_pdf)
     QPrinter *currentPrinter;
 #endif
+
+    QList<QSharedPointer<CertificateErrorController>> m_certificateErrorControllers;
 };
 
 class QContextMenuBuilder : public QtWebEngineCore::RenderViewContextMenuQt
diff --git a/src/webenginewidgets/doc/src/qwebenginepage_lgpl.qdoc b/src/webenginewidgets/doc/src/qwebenginepage_lgpl.qdoc
index 64fe4c9cd..5536c0058 100644
--- a/src/webenginewidgets/doc/src/qwebenginepage_lgpl.qdoc
+++ b/src/webenginewidgets/doc/src/qwebenginepage_lgpl.qdoc
@@ -522,6 +522,8 @@
     Return \c true to ignore the error and complete the request. Return \c false to stop loading
     the request.
 
+    \note If the error was successfully deferred then the returned value will be ignored.
+
     \sa QWebEngineCertificateError
 */