fdo-50672 Escape underscores in menus for unity

Change-Id: Ibb4647c1ff6c2858fea888efae975e8e5c5011e2
Reviewed-on: https://gerrit.libreoffice.org/8773Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/gtk/window/gtksalmenu.cxx

@@ -548,8 +548,10 @@ void GtkSalMenu::NativeSetEnableItem( gchar* aCommand, gboolean bEnable )
 void GtkSalMenu::NativeSetItemText( unsigned nSection, unsigned nItemPos, const OUString& rText )
 {
     SolarMutexGuard aGuard;
-    // Replace the '~' character with '_'.
-    OUString aText = rText.replace( '~', '_' );
+    // Escape all underscores so that they don't get interpreted as hotkeys
+    OUString aText = rText.replaceAll( "_", "__" );
+    // Replace the LibreOffice hotkey identifier with an underscore
+    aText = aText.replace( '~', '_' );
     OString aConvertedText = OUStringToOString( aText, RTL_TEXTENCODING_UTF8 );
 
     // Update item text only when necessary.