IOS/ES: Partially restore hack to fake IOS titles

This partially restores a hack which causes ES to fake ticket views for
IOS titles.

This is necessary because we still allow users to boot games from the
game list, so, with no way of making sure the required IOSes are
installed beforehand, games may OSPanic() when they try to reload to
some IOS version and just find out that the IOS is not installed
(something which *never* happens on the real console, of course).

A warning is printed in the logs to make sure technical users know the
IOS titles are being faked. To try and keep things accurate in all
other cases, this hack is only active when it is needed (when the
current title is a disc title which was launched from the game list).

Source/Core/Core/IOS/ES/ES.cpp

@@ -86,6 +86,12 @@ constexpr const u8* s_key_table[11] = {
     s_key_empty,  // Unknown
 };
 
+static bool IsDiscTitle(u64 title_id)
+{
+  return IsTitleType(title_id, IOS::ES::TitleType::Game) ||
+         IsTitleType(title_id, IOS::ES::TitleType::GameWithChannel);
+}
+
 ES::ES(u32 device_id, const std::string& device_name) : Device(device_id, device_name)
 {
 }
@@ -146,8 +152,7 @@ void TitleContext::Update(const IOS::ES::TMDReader& tmd_, const IOS::ES::TicketR
 
 void TitleContext::UpdateRunningGame() const
 {
-  if (IOS::ES::IsTitleType(tmd.GetTitleId(), IOS::ES::TitleType::Game) ||
+  if (IsDiscTitle(tmd.GetTitleId()))
-      IOS::ES::IsTitleType(tmd.GetTitleId(), IOS::ES::TitleType::GameWithChannel))
   {
     const u32 title_identifier = Common::swap32(static_cast<u32>(tmd.GetTitleId()));
     const u16 group_id = Common::swap16(tmd.GetGroupId());
@@ -1027,6 +1032,18 @@ IPCCommandResult ES::GetTitles(const IOCtlVRequest& request)
   return GetTitles(GetInstalledTitles(), request);
 }
 
+// HACK: Since we do not want to require users to install disc updates when launching
+//       Wii games from the game list (which is the inaccurate game boot path anyway),
+//       IOSes have to be faked for games which reload IOS to work properly.
+//       To minimize the effect of this hack, we should only do this for disc titles
+//       booted from the game list, though.
+static bool ShouldReturnFakeViewsForIOSes(u64 title_id)
+{
+  const bool ios = IsTitleType(title_id, IOS::ES::TitleType::System) && title_id != TITLEID_SYSMENU;
+  const bool disc_title = s_title_context.active && IsDiscTitle(s_title_context.tmd.GetTitleId());
+  return ios && SConfig::GetInstance().m_BootType == SConfig::BOOT_ISO && disc_title;
+}
+
 IPCCommandResult ES::GetViewCount(const IOCtlVRequest& request)
 {
   if (!request.HasNumberOfValidVectors(1, 1))
@@ -1041,6 +1058,11 @@ IPCCommandResult ES::GetViewCount(const IOCtlVRequest& request)
   {
     view_count = Loader.GetTicket().GetNumberOfTickets();
   }
+  else if (ShouldReturnFakeViewsForIOSes(TitleID))
+  {
+    view_count = 1;
+    WARN_LOG(IOS_ES, "GetViewCount: Faking IOS title %016" PRIx64 " being present", TitleID);
+  }
 
   INFO_LOG(IOS_ES, "IOCTL_ES_GETVIEWCNT for titleID: %08x/%08x (View Count = %zu)",
            static_cast<u32>(TitleID >> 32), static_cast<u32>(TitleID), view_count);
@@ -1069,6 +1091,11 @@ IPCCommandResult ES::GetViews(const IOCtlVRequest& request)
                         ticket_view.data(), ticket_view.size());
     }
   }
+  else if (ShouldReturnFakeViewsForIOSes(TitleID))
+  {
+    Memory::Memset(request.io_vectors[0].address, 0, sizeof(IOS::ES::TicketView));
+    WARN_LOG(IOS_ES, "GetViews: Faking IOS title %016" PRIx64 " being present", TitleID);
+  }
 
   INFO_LOG(IOS_ES, "IOCTL_ES_GETVIEWS for titleID: %08x/%08x (MaxViews = %i)", (u32)(TitleID >> 32),
            (u32)TitleID, maxViews);