Add settings to warn about large or multiline pastes

doc/cascadia/SettingsSchema.md

@@ -9,6 +9,8 @@ Properties listed below affect the entire window, regardless of the profile sett
 | `alwaysShowTabs` | _Required_ | Boolean | `true` | When set to `true`, tabs are always displayed. When set to `false` and `showTabsInTitlebar` is set to `false`, tabs only appear after typing <kbd>Ctrl</kbd> + <kbd>T</kbd>. |
 | `copyOnSelect` | Optional | Boolean | `false` | When set to `true`, a selection is immediately copied to your clipboard upon creation. When set to `false`, the selection persists and awaits further action. |
 | `copyFormatting` | Optional | Boolean | `false` | When set to `true`, the color and font formatting of selected text is also copied to your clipboard. When set to `false`, only plain text is copied to your clipboard. |
+| `largePasteWarning` | Optional | Boolean | `true` | When set to `true`, trying to paste text with more than 5 KiB of characters will display a warning asking you whether to continue or not with the paste. |
+| `multiLinePasteWarning` | Optional | Boolean | `true` | When set to `true`, trying to paste text with a _new line_ character will display a warning asking you whether to continue or not with the paste. |
 | `defaultProfile` | _Required_ | String | PowerShell guid | Sets the default profile. Opens by typing <kbd>Ctrl</kbd> + <kbd>T</kbd> or by clicking the '+' icon. The guid of the desired default profile is used as the value. |
 | `initialCols` | _Required_ | Integer | `120` | The number of columns displayed in the window upon first load. |
 | `initialPosition` | Optional | String | `","` | The position of the top left corner of the window upon first load. On a system with multiple displays, these coordinates are relative to the top left of the primary display. If `launchMode` is set to `"maximized"`, the window will be maximized on the monitor specified by those coordinates. |

doc/cascadia/profiles.schema.json

@@ -316,6 +316,16 @@
           "description": "When set to `true`, the color and font formatting of selected text is also copied to your clipboard. When set to `false`, only plain text is copied to your clipboard.",
           "type": "boolean"
         },
+        "largePasteWarning": {
+          "default": true,
+          "description": "When set to true, trying to paste text with more than 5 KiB of characters will display a warning asking you whether to continue or not with the paste.",
+          "type": "boolean"
+        },
+        "multiLinePasteWarning": {
+          "default": true,
+          "description": "When set to true, trying to paste text with a \"new line\" character will display a warning asking you whether to continue or not with the paste.",
+          "type": "boolean"
+        },
         "defaultProfile": {
           "description": "Sets the default profile. Opens by clicking the \"+\" icon or typing the key binding assigned to \"newTab\".",
           "type": "string"

src/cascadia/TerminalApp/GlobalAppSettings.cpp

@@ -31,6 +31,8 @@ static constexpr std::string_view ShowTabsInTitlebarKey{ "showTabsInTitlebar" };
 static constexpr std::string_view WordDelimitersKey{ "wordDelimiters" };
 static constexpr std::string_view CopyOnSelectKey{ "copyOnSelect" };
 static constexpr std::string_view CopyFormattingKey{ "copyFormatting" };
+static constexpr std::string_view WarnAboutLargePasteKey{ "largePasteWarning" };
+static constexpr std::string_view WarnAboutMultiLinePasteKey{ "multiLinePasteWarning" };
 static constexpr std::string_view LaunchModeKey{ "launchMode" };
 static constexpr std::string_view ConfirmCloseAllKey{ "confirmCloseAllTabs" };
 static constexpr std::string_view SnapToGridOnResizeKey{ "snapToGridOnResize" };
@@ -190,6 +192,10 @@ void GlobalAppSettings::LayerJson(const Json::Value& json)
 
     JsonUtils::GetBool(json, CopyFormattingKey, _CopyFormatting);
 
+    JsonUtils::GetBool(json, WarnAboutLargePasteKey, _WarnAboutLargePaste);
+
+    JsonUtils::GetBool(json, WarnAboutMultiLinePasteKey, _WarnAboutMultiLinePaste);
+
     if (auto launchMode{ json[JsonKey(LaunchModeKey)] })
     {
         _LaunchMode = _ParseLaunchMode(GetWstringFromJson(launchMode));

src/cascadia/TerminalApp/GlobalAppSettings.h

@@ -72,6 +72,8 @@ class TerminalApp::GlobalAppSettings final
     GETSET_PROPERTY(std::wstring, WordDelimiters); // default value set in constructor
     GETSET_PROPERTY(bool, CopyOnSelect, false);
     GETSET_PROPERTY(bool, CopyFormatting, false);
+    GETSET_PROPERTY(bool, WarnAboutLargePaste, true);
+    GETSET_PROPERTY(bool, WarnAboutMultiLinePaste, true);
     GETSET_PROPERTY(LaunchPosition, InitialPosition);
     GETSET_PROPERTY(winrt::TerminalApp::LaunchMode, LaunchMode, winrt::TerminalApp::LaunchMode::DefaultMode);
     GETSET_PROPERTY(bool, SnapToGridOnResize, true);

src/cascadia/TerminalApp/Resources/en-US/Resources.resw

@@ -347,4 +347,28 @@
     <value>Command Prompt</value>
     <comment>This is the name of "Command Prompt", as localized in Windows. The localization here should match the one in the Windows product for "Command Prompt"</comment>
   </data>
+  <data name="LargePasteDialog.CloseButtonText" xml:space="preserve">
+    <value>Cancel</value>
+  </data>
+    <data name="LargePasteDialog.Content" xml:space="preserve">
+    <value>You are about to paste text that is longer than 5 KiB. This can make the terminal unresponsive while the text is being received on the other end. Are you sure you want to continue?</value>
+  </data>
+    <data name="LargePasteDialog.PrimaryButtonText" xml:space="preserve">
+    <value>Paste anyway</value>
+  </data>
+    <data name="LargePasteDialog.Title" xml:space="preserve">
+    <value>Warning</value>
+  </data>
+    <data name="MultiLinePasteDialog.CloseButtonText" xml:space="preserve">
+    <value>Cancel</value>
+  </data>
+    <data name="MultiLinePasteDialog.Content" xml:space="preserve">
+    <value>You are about to paste text that contains the "new line" character. If you paste text that contains the "new line" character into a shell, one or more command(s) will be executed automatically upon paste. Are you sure you want to continue?</value>
+  </data>
+    <data name="MultiLinePasteDialog.PrimaryButtonText" xml:space="preserve">
+    <value>Paste anyway</value>
+  </data>
+    <data name="MultiLinePasteDialog.Title" xml:space="preserve">
+    <value>Warning</value>
+  </data>
 </root>

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -288,6 +288,30 @@ namespace winrt::TerminalApp::implementation
         _showDialogHandlers(*this, FindName(L"CloseAllDialog").try_as<WUX::Controls::ContentDialog>());
     }
 
+    // Method Description:
+    // - Displays a dialog to warn the user about the fact that the text that
+    //   they are trying to paste contains the "new line" character which can
+    //   have the effect of starting commands without the user's knowledge if
+    //   it is pasted on a shell where the "new line" character marks the end
+    //   of a command.
+    // - Only one dialog can be visible at a time. If another dialog is visible
+    //   when this is called, nothing happens. See _ShowDialog for details
+    void TerminalPage::_ShowMultiLinePasteWarningDialog()
+    {
+        _showDialogHandlers(*this, FindName(L"MultiLinePasteDialog").try_as<WUX::Controls::ContentDialog>());
+    }
+
+    // Method Description:
+    // - Displays a dialog to warn the user about the fact that the text that
+    //   they are trying to paste is very long, in case they did not mean to
+    //   paste it but pressed the paste shortcut by accident.
+    // - Only one dialog can be visible at a time. If another dialog is visible
+    //   when this is called, nothing happens. See _ShowDialog for details
+    void TerminalPage::_ShowLargePasteWarningDialog()
+    {
+        _showDialogHandlers(*this, FindName(L"LargePasteDialog").try_as<WUX::Controls::ContentDialog>());
+    }
+
     // Method Description:
     // - Builds the flyout (dropdown) attached to the new tab button, and
     //   attaches it to the button. Populates the flyout with one entry per
@@ -1472,26 +1496,19 @@ namespace winrt::TerminalApp::implementation
         CATCH_LOG();
     }
 
-    // Method Description:
-    // - Fires an async event to get data from the clipboard, and paste it to
-    //   the terminal. Triggered when the Terminal Control requests clipboard
-    //   data with it's PasteFromClipboard event.
-    // Arguments:
-    // - eventArgs: the PasteFromClipboard event sent from the TermControl
-    winrt::fire_and_forget TerminalPage::_PasteFromClipboardHandler(const IInspectable /*sender*/,
-                                                                    const PasteFromClipboardEventArgs eventArgs)
-    {
-        co_await winrt::resume_foreground(Dispatcher(), CoreDispatcherPriority::High);
-
-        TerminalPage::PasteFromClipboard(eventArgs);
-    }
-
     // Function Description:
-    // - Copies and processes the text data from the Windows Clipboard.
-    //   Does some of this in a background thread, as to not hang/crash the UI thread.
+    // - This function is called when the `TermControl` requests that we send
+    //   it the clipboard's content.
+    // - Retrieves the data from the Windows Clipboard and converts it to text.
+    // - Shows warnings if the clipboard is too big or contains multiple lines
+    //   of text.
+    // - Sends the text back to the TermControl through the event's
+    //   `HandleClipboardData` member function.
+    // - Does some of this in a background thread, as to not hang/crash the UI thread.
     // Arguments:
     // - eventArgs: the PasteFromClipboard event sent from the TermControl
-    fire_and_forget TerminalPage::PasteFromClipboard(PasteFromClipboardEventArgs eventArgs)
+    fire_and_forget TerminalPage::_PasteFromClipboardHandler(const IInspectable /*sender*/,
+                                                             const PasteFromClipboardEventArgs eventArgs)
     {
         const DataPackageView data = Clipboard::GetContent();
 
@@ -1517,7 +1534,34 @@ namespace winrt::TerminalApp::implementation
                     text = item.Path();
                 }
             }
-            eventArgs.HandleClipboardData(text);
+
+            co_await winrt::resume_foreground(Dispatcher());
+
+            const bool hasNewLine = std::find(text.cbegin(), text.cend(), L'\n') != text.cend();
+            const bool warnMultiLine = hasNewLine && _settings->GlobalSettings().WarnAboutMultiLinePaste();
+
+            constexpr const std::size_t minimumSizeForWarning = 1024 * 5; // 5 KiB
+            const bool warnLargeText = text.size() > minimumSizeForWarning &&
+                                       _settings->GlobalSettings().WarnAboutLargePaste();
+
+            if (!warnMultiLine && !warnLargeText)
+            {
+                eventArgs.HandleClipboardData(text);
+                co_return;
+            }
+
+            _acceptPaste = [=]() {
+                eventArgs.HandleClipboardData(text);
+            };
+
+            if (warnMultiLine)
+            {
+                _ShowMultiLinePasteWarningDialog();
+            }
+            else if (warnLargeText)
+            {
+                _ShowLargePasteWarningDialog();
+            }
         }
         CATCH_LOG();
     }
@@ -1721,6 +1765,36 @@ namespace winrt::TerminalApp::implementation
         _CloseAllTabs();
     }
 
+    // Method Description:
+    // - Called when the user wants to paste the text anyway after a paste
+    //   warning.
+    // - Sends the clipboard's text to the `TermControl`.
+    // Arguments:
+    // - sender: unused
+    // - ContentDialogButtonClickEventArgs: unused
+    void TerminalPage::_AcceptPasteButtonOnClick(WUX::Controls::ContentDialog /* sender */,
+                                                 WUX::Controls::ContentDialogButtonClickEventArgs /* eventArgs*/)
+    {
+        if (_acceptPaste)
+        {
+            _acceptPaste();
+            _acceptPaste = nullptr;
+        }
+    }
+
+    // Method Description:
+    // - Called when the user closes a warning dialog about pasting text.
+    // - Destroys the callback to send the clipboard's text to the
+    //   `TermControl` because the user cancelled the paste operation.
+    // Arguments:
+    // - sender: unused
+    // - ContentDialogButtonClickEventArgs: unused
+    void TerminalPage::_RejectPasteButtonOnClick(WUX::Controls::ContentDialog /* sender */,
+                                                 WUX::Controls::ContentDialogButtonClickEventArgs /* eventArgs*/)
+    {
+        _acceptPaste = nullptr;
+    }
+
     // Method Description:
     // - Hook up keybindings, and refresh the UI of the terminal.
     //   This includes update the settings of all the tabs according

src/cascadia/TerminalApp/TerminalPage.h

@@ -95,8 +95,12 @@ namespace winrt::TerminalApp::implementation
         std::deque<winrt::TerminalApp::ActionAndArgs> _startupActions;
         winrt::fire_and_forget _ProcessStartupActions();
 
+        std::function<void()> _acceptPaste;
+
         void _ShowAboutDialog();
         void _ShowCloseWarningDialog();
+        void _ShowMultiLinePasteWarningDialog();
+        void _ShowLargePasteWarningDialog();
 
         void _CreateNewTabFlyout();
         void _OpenNewTabDropdown();
@@ -108,6 +112,8 @@ namespace winrt::TerminalApp::implementation
         void _FeedbackButtonOnClick(const IInspectable& sender, const Windows::UI::Xaml::RoutedEventArgs& eventArgs);
         void _AboutButtonOnClick(const IInspectable& sender, const Windows::UI::Xaml::RoutedEventArgs& eventArgs);
         void _CloseWarningPrimaryButtonOnClick(Windows::UI::Xaml::Controls::ContentDialog sender, Windows::UI::Xaml::Controls::ContentDialogButtonClickEventArgs eventArgs);
+        void _AcceptPasteButtonOnClick(Windows::UI::Xaml::Controls::ContentDialog sender, Windows::UI::Xaml::Controls::ContentDialogButtonClickEventArgs eventArgs);
+        void _RejectPasteButtonOnClick(Windows::UI::Xaml::Controls::ContentDialog sender, Windows::UI::Xaml::Controls::ContentDialogButtonClickEventArgs eventArgs);
         void _ThirdPartyNoticesOnClick(const IInspectable& sender, const Windows::UI::Xaml::RoutedEventArgs& eventArgs);
 
         void _HookupKeyBindings(TerminalApp::AppKeyBindings bindings) noexcept;
@@ -149,7 +155,6 @@ namespace winrt::TerminalApp::implementation
                                                           const Microsoft::Terminal::TerminalControl::PasteFromClipboardEventArgs eventArgs);
         bool _CopyText(const bool trimTrailingWhitespace);
         void _PasteText();
-        static fire_and_forget PasteFromClipboard(winrt::Microsoft::Terminal::TerminalControl::PasteFromClipboardEventArgs eventArgs);
 
         fire_and_forget _LaunchSettings(const winrt::TerminalApp::SettingsTarget target);
 

src/cascadia/TerminalApp/TerminalPage.xaml

@@ -53,5 +53,23 @@ the MIT License. See LICENSE in the project root for license information. -->
             DefaultButton="Primary"
             PrimaryButtonClick="_CloseWarningPrimaryButtonOnClick">
         </ContentDialog>
+
+        <ContentDialog
+            x:Load="False"
+            x:Name="MultiLinePasteDialog"
+            x:Uid="MultiLinePasteDialog"
+            DefaultButton="Primary"
+            PrimaryButtonClick="_AcceptPasteButtonOnClick"
+            CloseButtonClick="_RejectPasteButtonOnClick">
+        </ContentDialog>
+
+        <ContentDialog
+            x:Load="False"
+            x:Name="LargePasteDialog"
+            x:Uid="LargePasteDialog"
+            DefaultButton="Primary"
+            PrimaryButtonClick="_AcceptPasteButtonOnClick"
+            CloseButtonClick="_RejectPasteButtonOnClick">
+        </ContentDialog>
     </Grid>
 </Page>