Fix embedded PDFs when plugins are disabled

Cover all cases from https://pdfobject.com/static

- Plugin placeholder is generally broken: displays garbage and crashes
on interaction.  Fix it and show when PDFs are included by <embed>
or <object> tags.

- Do not start an automatical download when the disabled PDF plugin
was requested by an iframe. Show a clickable placeholder and let the
end-users start it manually.

- Remove unused class PluginPlaceholderQt

Task-number: QTBUG-76314
Change-Id: I01a0c93ab23f54e4272f5aeb30578de0dcf18932
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

7 files changed, 264 insertions, 104 deletions

diff --git a/src/core/content_browser_client_qt.cpp b/src/core/content_browser_client_qt.cpp
index c2c78ff8b..da1ea8dde 100644
--- a/src/core/content_browser_client_qt.cpp
+++ b/src/core/content_browser_client_qt.cpp
@@ -167,6 +167,7 @@
 #include "extensions/common/manifest_handlers/mime_types_handler.h"
 #include "extensions/extension_web_contents_observer_qt.h"
 #include "extensions/extensions_browser_client_qt.h"
+#include "extensions/pdf_iframe_navigation_throttle_qt.h"
 #include "net/plugin_response_interceptor_url_loader_throttle.h"
 #endif
 
@@ -222,6 +223,13 @@ bool IsHandledProtocol(base::StringPiece scheme)
 
 namespace QtWebEngineCore {
 
+void MaybeAddThrottle(
+    std::unique_ptr<content::NavigationThrottle> maybe_throttle,
+    std::vector<std::unique_ptr<content::NavigationThrottle>>* throttles) {
+    if (maybe_throttle)
+        throttles->push_back(std::move(maybe_throttle));
+}
+
 class QtShareGLContext : public gl::GLContext {
 public:
     QtShareGLContext(QOpenGLContext *qtContext)
@@ -1012,6 +1020,11 @@ std::vector<std::unique_ptr<content::NavigationThrottle>> ContentBrowserClientQt
                             navigation_handle,
                             base::BindRepeating(&navigationThrottleCallback),
                             navigation_interception::SynchronyMode::kSync));
+
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+    MaybeAddThrottle(extensions::PDFIFrameNavigationThrottleQt::MaybeCreateThrottleFor(navigation_handle), &throttles);
+#endif
+
     return throttles;
 }
 
diff --git a/src/core/core_chromium.pri b/src/core/core_chromium.pri
index 108dd3221..e978d20a1 100644
--- a/src/core/core_chromium.pri
+++ b/src/core/core_chromium.pri
@@ -113,7 +113,6 @@ SOURCES = \
         renderer/web_engine_page_render_frame.cpp \
         renderer/render_configuration.cpp \
         renderer/user_resource_controller.cpp \
-        renderer/plugins/plugin_placeholder_qt.cpp \
         renderer_host/web_engine_page_host.cpp \
         renderer_host/user_resource_controller_host.cpp \
         resource_bundle_qt.cpp \
@@ -218,7 +217,6 @@ HEADERS = \
         renderer/web_engine_page_render_frame.h \
         renderer/render_configuration.h \
         renderer/user_resource_controller.h \
-        renderer/plugins/plugin_placeholder_qt.h \
         renderer_host/web_engine_page_host.h \
         renderer_host/user_resource_controller_host.h \
         request_controller.h \
@@ -326,6 +324,7 @@ qtConfig(webengine-extensions) {
         extensions/extensions_browser_client_qt.cpp \
         extensions/messaging_delegate_qt.cpp \
         extensions/mime_handler_view_guest_delegate_qt.cpp \
+        extensions/pdf_iframe_navigation_throttle_qt.cpp \
         extensions/plugin_service_filter_qt.cpp \
         net/plugin_response_interceptor_url_loader_throttle.cpp \
         renderer/extensions/extensions_dispatcher_delegate_qt.cpp \
@@ -345,6 +344,7 @@ qtConfig(webengine-extensions) {
         extensions/extensions_browser_client_qt.h \
         extensions/messaging_delegate_qt.h \
         extensions/mime_handler_view_guest_delegate_qt.h \
+        extensions/pdf_iframe_navigation_throttle_qt.h \
         extensions/plugin_service_filter_qt.h \
         net/plugin_response_interceptor_url_loader_throttle.h \
         renderer/extensions/extensions_dispatcher_delegate_qt.h \
diff --git a/src/core/extensions/pdf_iframe_navigation_throttle_qt.cpp b/src/core/extensions/pdf_iframe_navigation_throttle_qt.cpp
new file mode 100644
index 000000000..7c2fe75f0
--- /dev/null
+++ b/src/core/extensions/pdf_iframe_navigation_throttle_qt.cpp
@@ -0,0 +1,219 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+// based on //chrome/browser/plugins/pdf_iframe_navigation_throttle.cc
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+
+#include "extensions/pdf_iframe_navigation_throttle_qt.h"
+
+#include "chrome/grit/renderer_resources.h"
+#include "components/strings/grit/components_strings.h"
+#include "content/public/browser/download_utils.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/plugin_service.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_user_data.h"
+#include "content/public/common/webplugininfo.h"
+#include "net/base/escape.h"
+#include "net/http/http_response_headers.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/base/webui/jstemplate_builder.h"
+#include "ui/base/webui/web_ui_util.h"
+
+namespace extensions {
+
+constexpr char kPDFMimeType[] = "application/pdf";
+
+// Used to scope the posted navigation task to the lifetime of |web_contents|.
+class PdfWebContentsLifetimeHelper : public content::WebContentsUserData<PdfWebContentsLifetimeHelper>
+{
+public:
+    explicit PdfWebContentsLifetimeHelper(content::WebContents *web_contents)
+        : web_contents_(web_contents)
+    {}
+
+    base::WeakPtr<PdfWebContentsLifetimeHelper> GetWeakPtr()
+    {
+        return weak_factory_.GetWeakPtr();
+    }
+
+    void NavigateIFrameToPlaceholder(const content::OpenURLParams &url_params)
+    {
+        web_contents_->OpenURL(url_params);
+    }
+
+private:
+    friend class content::WebContentsUserData<PdfWebContentsLifetimeHelper>;
+
+    content::WebContents* const web_contents_;
+    base::WeakPtrFactory<PdfWebContentsLifetimeHelper> weak_factory_{this};
+
+    WEB_CONTENTS_USER_DATA_KEY_DECL();
+};
+
+WEB_CONTENTS_USER_DATA_KEY_IMPL(PdfWebContentsLifetimeHelper)
+
+bool IsPDFPluginEnabled(content::NavigationHandle *navigation_handle, bool *is_stale)
+{
+    content::WebContents *web_contents = navigation_handle->GetWebContents();
+    int process_id = web_contents->GetMainFrame()->GetProcess()->GetID();
+    int routing_id = web_contents->GetMainFrame()->GetRoutingID();
+    content::WebPluginInfo plugin_info;
+    // Will check WebEngineSettings by PluginServiceFilterQt
+    return content::PluginService::GetInstance()->GetPluginInfo(
+        process_id, routing_id, navigation_handle->GetURL(),
+        web_contents->GetMainFrame()->GetLastCommittedOrigin(), kPDFMimeType,
+        false /* allow_wildcard */, is_stale, &plugin_info,
+        nullptr /* actual_mime_type */);
+}
+
+std::string GetPDFPlaceholderHTML(const GURL &pdf_url)
+{
+    std::string template_html = ui::ResourceBundle::GetSharedInstance().LoadDataResourceString(IDR_PDF_PLUGIN_HTML);
+    webui::AppendWebUiCssTextDefaults(&template_html);
+
+    base::DictionaryValue values;
+    values.SetString("fileName", pdf_url.ExtractFileName());
+    values.SetString("open", l10n_util::GetStringUTF8(IDS_ACCNAME_OPEN));
+    values.SetString("pdfUrl", pdf_url.spec());
+
+    return webui::GetI18nTemplateHtml(template_html, &values);
+}
+
+// static
+std::unique_ptr<content::NavigationThrottle>
+PDFIFrameNavigationThrottleQt::MaybeCreateThrottleFor(content::NavigationHandle *handle)
+{
+    if (handle->IsInMainFrame())
+        return nullptr;
+    return std::make_unique<PDFIFrameNavigationThrottleQt>(handle);
+}
+
+PDFIFrameNavigationThrottleQt::PDFIFrameNavigationThrottleQt(content::NavigationHandle *handle)
+    : content::NavigationThrottle(handle)
+{
+}
+
+PDFIFrameNavigationThrottleQt::~PDFIFrameNavigationThrottleQt()
+{
+}
+
+content::NavigationThrottle::ThrottleCheckResult PDFIFrameNavigationThrottleQt::WillProcessResponse()
+{
+    const net::HttpResponseHeaders *response_headers = navigation_handle()->GetResponseHeaders();
+    if (!response_headers)
+        return content::NavigationThrottle::PROCEED;
+
+    std::string mime_type;
+    response_headers->GetMimeType(&mime_type);
+    if (mime_type != kPDFMimeType)
+        return content::NavigationThrottle::PROCEED;
+
+    // We MUST download responses marked as attachments rather than showing
+    // a placeholder.
+    if (content::download_utils::MustDownload(navigation_handle()->GetURL(), response_headers, mime_type))
+        return content::NavigationThrottle::PROCEED;
+
+    bool is_stale = false;
+    bool pdf_plugin_enabled = IsPDFPluginEnabled(navigation_handle(), &is_stale);
+
+    if (is_stale) {
+        // On browser start, the plugin list may not be ready yet.
+        content::PluginService::GetInstance()->GetPlugins(
+            base::BindOnce(&PDFIFrameNavigationThrottleQt::OnPluginsLoaded,
+                           weak_factory_.GetWeakPtr()));
+        return content::NavigationThrottle::DEFER;
+    }
+
+    // If the plugin was found, proceed on the navigation. Otherwise fall through
+    // to the placeholder case.
+    if (pdf_plugin_enabled)
+        return content::NavigationThrottle::PROCEED;
+
+    LoadPlaceholderHTML();
+    return content::NavigationThrottle::CANCEL_AND_IGNORE;
+}
+
+const char *PDFIFrameNavigationThrottleQt::GetNameForLogging()
+{
+    return "PDFIFrameNavigationThrottleQt";
+}
+
+void PDFIFrameNavigationThrottleQt::OnPluginsLoaded(
+                        const std::vector<content::WebPluginInfo> &plugins)
+{
+    if (IsPDFPluginEnabled(navigation_handle(), nullptr /* is_stale */)) {
+        Resume();
+    } else {
+        LoadPlaceholderHTML();
+        CancelDeferredNavigation(content::NavigationThrottle::CANCEL_AND_IGNORE);
+    }
+}
+
+void PDFIFrameNavigationThrottleQt::LoadPlaceholderHTML()
+{
+    // Prepare the params to navigate to the placeholder.
+    std::string html = GetPDFPlaceholderHTML(navigation_handle()->GetURL());
+    GURL data_url("data:text/html," + net::EscapePath(html));
+    content::OpenURLParams params = content::OpenURLParams::FromNavigationHandle(navigation_handle());
+    params.url = data_url;
+    params.transition = ui::PAGE_TRANSITION_AUTO_SUBFRAME;
+
+    // Post a task to navigate to the placeholder HTML. We don't navigate
+    // synchronously here, as starting a navigation within a navigation is
+    // an antipattern. Use a helper object scoped to the WebContents lifetime to
+    // scope the navigation task to the WebContents lifetime.
+    content::WebContents *web_contents = navigation_handle()->GetWebContents();
+    if (!web_contents)
+        return;
+
+    PdfWebContentsLifetimeHelper::CreateForWebContents(web_contents);
+    PdfWebContentsLifetimeHelper *helper = PdfWebContentsLifetimeHelper::FromWebContents(web_contents);
+    base::SequencedTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::BindOnce(&PdfWebContentsLifetimeHelper::NavigateIFrameToPlaceholder,
+                       helper->GetWeakPtr(), std::move(params)));
+}
+
+} // namespace extensions
diff --git a/src/core/renderer/plugins/plugin_placeholder_qt.h b/src/core/extensions/pdf_iframe_navigation_throttle_qt.h
index a99c0d045..37f5bf1d6 100644
--- a/src/core/renderer/plugins/plugin_placeholder_qt.h
+++ b/src/core/extensions/pdf_iframe_navigation_throttle_qt.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2020 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWebEngine module of the Qt Toolkit.
@@ -37,42 +37,46 @@
 **
 ****************************************************************************/
 
-// Copyright 2013 The Chromium Authors. All rights reserved.
+// based on //chrome/browser/plugins/pdf_iframe_navigation_throttle.h
+// Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef PLUGIN_PLACEHOLDER_QT_H
-#define PLUGIN_PLACEHOLDER_QT_H
+#ifndef PDF_IFRAME_NAVIGATION_THROTTLE_QT
+#define PDF_IFRAME_NAVIGATION_THROTTLE_QT
 
-#include "base/macros.h"
-#include "components/plugins/renderer/plugin_placeholder.h"
-#include "gin/handle.h"
-#include "gin/wrappable.h"
-#include "third_party/blink/public/web/web_plugin_params.h"
+#include "content/public/browser/navigation_throttle.h"
 
-namespace QtWebEngineCore {
+#include "base/memory/weak_ptr.h"
 
-// A basic placeholder that supports only hiding.
-class PluginPlaceholderQt final : public plugins::PluginPlaceholderBase
-                                , public gin::Wrappable<PluginPlaceholderQt>
+namespace content {
+class NavigationHandle;
+struct WebPluginInfo;
+}
+
+namespace extensions {
+
+// This class prevents automatical download of PDFs when they are embedded
+// in subframes and plugins are disabled in API.
+class PDFIFrameNavigationThrottleQt : public content::NavigationThrottle
 {
 public:
-    static gin::WrapperInfo kWrapperInfo;
+    static std::unique_ptr<content::NavigationThrottle> MaybeCreateThrottleFor(content::NavigationHandle *handle);
+
+    explicit PDFIFrameNavigationThrottleQt(content::NavigationHandle *handle);
+    ~PDFIFrameNavigationThrottleQt() override;
 
-    PluginPlaceholderQt(content::RenderFrame* render_frame,
-                        const blink::WebPluginParams& params,
-                        const std::string& html_data);
-    ~PluginPlaceholderQt() override;
+    // content::NavigationThrottle
+    content::NavigationThrottle::ThrottleCheckResult WillProcessResponse() override;
+    const char *GetNameForLogging() override;
 
 private:
-    // WebViewPlugin::Delegate methods:
-    v8::Local<v8::Value> GetV8Handle(v8::Isolate* isolate) final;
+    void OnPluginsLoaded(const std::vector<content::WebPluginInfo> &plugins);
+    void LoadPlaceholderHTML();
 
-    // gin::Wrappable method:
-    gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
-        v8::Isolate* isolate) override;
+    base::WeakPtrFactory<PDFIFrameNavigationThrottleQt> weak_factory_{this};
 };
 
-}  // namespace QtWebEngineCore
+} // namespace extensions
 
-#endif  // PLUGIN_PLACEHOLDER_QT_H
+#endif // PDF_IFRAME_NAVIGATION_THROTTLE_QT
diff --git a/src/core/renderer/content_renderer_client_qt.cpp b/src/core/renderer/content_renderer_client_qt.cpp
index 317fde8f7..28815b5c1 100644
--- a/src/core/renderer/content_renderer_client_qt.cpp
+++ b/src/core/renderer/content_renderer_client_qt.cpp
@@ -97,7 +97,6 @@
 
 #if BUILDFLAG(ENABLE_PLUGINS)
 #include "plugins/loadable_plugin_placeholder_qt.h"
-#include "plugins/plugin_placeholder_qt.h"
 #include "content/common/frame_messages.h"
 #endif // ENABLE_PLUGINS
 
diff --git a/src/core/renderer/plugins/loadable_plugin_placeholder_qt.cpp b/src/core/renderer/plugins/loadable_plugin_placeholder_qt.cpp
index b43d9a24b..9dc5fbd94 100644
--- a/src/core/renderer/plugins/loadable_plugin_placeholder_qt.cpp
+++ b/src/core/renderer/plugins/loadable_plugin_placeholder_qt.cpp
@@ -77,7 +77,7 @@ LoadablePluginPlaceholderQt::~LoadablePluginPlaceholderQt()
 LoadablePluginPlaceholderQt* LoadablePluginPlaceholderQt::CreateLoadableMissingPlugin(content::RenderFrame* render_frame,
                                                                                       const blink::WebPluginParams& params)
 {
-    const base::StringPiece template_html(ui::ResourceBundle::GetSharedInstance().GetRawDataResource(IDR_BLOCKED_PLUGIN_HTML));
+    std::string template_html(ui::ResourceBundle::GetSharedInstance().LoadDataResourceString(IDR_BLOCKED_PLUGIN_HTML));
 
     base::DictionaryValue values;
     values.SetString("name", "");
diff --git a/src/core/renderer/plugins/plugin_placeholder_qt.cpp b/src/core/renderer/plugins/plugin_placeholder_qt.cpp
deleted file mode 100644
index a72c29873..000000000
--- a/src/core/renderer/plugins/plugin_placeholder_qt.cpp
+++ /dev/null
@@ -1,75 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2020 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtWebEngine module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "plugin_placeholder_qt.h"
-
-#include "content/public/renderer/render_frame.h"
-#include "content/public/renderer/v8_value_converter.h"
-#include "gin/object_template_builder.h"
-
-namespace QtWebEngineCore {
-
-// static
-gin::WrapperInfo PluginPlaceholderQt::kWrapperInfo = {gin::kEmbedderNativeGin};
-
-PluginPlaceholderQt::PluginPlaceholderQt(content::RenderFrame* render_frame,
-                                         const blink::WebPluginParams& params,
-                                         const std::string& html_data)
-    : PluginPlaceholderBase(render_frame, params, html_data)
-{}
-
-PluginPlaceholderQt::~PluginPlaceholderQt() {}
-
-v8::Local<v8::Value> PluginPlaceholderQt::GetV8Handle(v8::Isolate* isolate)
-{
-    return gin::CreateHandle(isolate, this).ToV8();
-}
-
-gin::ObjectTemplateBuilder PluginPlaceholderQt::GetObjectTemplateBuilder(v8::Isolate* isolate)
-{
-    return gin::Wrappable<PluginPlaceholderQt>::GetObjectTemplateBuilder(isolate)
-        .SetMethod<void (QtWebEngineCore::PluginPlaceholderQt::*)()>(
-            "hide", &PluginPlaceholderQt::HideCallback);
-}
-
-}  // namespace QtWebEngineCore