CTitleStateIntro_patches: display error message on corrupted save data

TitleMenuRemoveContinueOnCorruptSaveMidAsmHook by @DeaTh-G

Co-Authored-By: DeaTh-G <55578911+DeaTh-G@users.noreply.github.com>

UnleashedRecomp/app.h

@@ -9,6 +9,7 @@ public:
     static inline bool s_isMissingDLC;
     static inline bool s_isLoading;
     static inline bool s_isWerehog;
+    static inline bool s_isSaveDataCorrupt;
 
     static inline ELanguage s_language;
 

UnleashedRecomp/locale/locale.cpp

@@ -342,6 +342,20 @@ std::unordered_map<std::string, std::unordered_map<ELanguage, std::string>> g_lo
             { ELanguage::Italian, "Sei sicuro di voler uscire?" }
         }
     },
+    {
+        // Notes: message appears when the SYS-DATA is corrupted (mismatching file size).
+        // To make this occur, open the file in any editor and just remove a large chunk of data.
+        // Do not localise this unless absolutely necessary, these strings are from the XEX.
+        "Title_Message_SaveDataCorrupt",
+        {
+            { ELanguage::English, "The save file appears to be\ncorrupted and cannot be loaded." },
+            { ELanguage::Japanese, "ゲームデータの読み込みに失敗しました。\nこのまま続けるとゲームデータをセーブすることはできません" },
+            { ELanguage::German, "Diese Speicherdatei ist beschädigt\nund kann nicht geladen werden." },
+            { ELanguage::French, "Le fichier de sauvegarde semble être\nendommagé et ne peut être chargé." },
+            { ELanguage::Spanish, "El archivo parece estar dañado\ny no se puede cargar." },
+            { ELanguage::Italian, "I file di salvataggio sembrano danneggiati\ne non possono essere caricati." }
+        }
+    },
     {
         "Common_On",
         {

UnleashedRecomp/patches/misc_patches.cpp

@@ -49,8 +49,6 @@ void WerehogBattleMusicMidAsmHook(PPCRegister& r11)
         r11.u8 = 3;
 }
 
-void StorageDevicePromptMidAsmHook() {}
-
 /* Hook function that gets the game region
    and force result to zero for Japanese
    to display the correct logos. */

UnleashedRecomp/patches/resident_patches.cpp

@@ -69,6 +69,8 @@ PPC_FUNC(sub_824E5170)
 
     if (pSaveIcon->m_IsVisible)
     {
+        App::s_isSaveDataCorrupt = false;
+
         if (!m_isSavedAchievementData)
         {
             LOGN("Saving achievements...");

UnleashedRecomp/patches/ui/CTitleStateIntro_patches.cpp

@@ -2,14 +2,21 @@
 #include <locale/locale.h>
 #include <ui/fader.h>
 #include <ui/message_window.h>
+#include <user/paths.h>
 #include <app.h>
 
 static bool g_quitMessageOpen = false;
 static bool g_quitMessageFaderBegun = false;
 static int g_quitMessageResult = -1;
 
+static std::atomic<bool> g_corruptSaveMessageOpen = false;
+static int g_corruptSaveMessageResult = -1;
+
 static bool ProcessQuitMessage()
 {
+    if (g_corruptSaveMessageOpen)
+        return false;
+
     if (!g_quitMessageOpen)
         return false;
 
@@ -37,6 +44,49 @@ static bool ProcessQuitMessage()
     return true;
 }
 
+static bool ProcessCorruptSaveMessage()
+{
+    if (!g_corruptSaveMessageOpen)
+        return false;
+
+    if (MessageWindow::Open(Localise("Title_Message_SaveDataCorrupt"), &g_corruptSaveMessageResult) == MSG_CLOSED)
+    {
+        g_corruptSaveMessageOpen = false;
+        g_corruptSaveMessageOpen.notify_one();
+        g_corruptSaveMessageResult = -1;
+    }
+
+    return true;
+}
+
+void StorageDevicePromptMidAsmHook() {}
+
+// Save data validation hook.
+PPC_FUNC_IMPL(__imp__sub_822C4330);
+PPC_FUNC(sub_822C4330)
+{
+    std::error_code ec;
+    auto saveFileSize = std::filesystem::file_size(GetSaveFilePath(true), ec);
+
+    auto expectedSize = ctx.r5.u32;
+    auto expectedSizeAdd = *(be<uint32_t>*)g_memory.Translate(0x83262110);
+
+    // TODO: check for backups here and restore them?
+    if (saveFileSize != expectedSize + expectedSizeAdd)
+    {
+        App::s_isSaveDataCorrupt = true;
+
+        g_corruptSaveMessageOpen = true;
+        g_corruptSaveMessageOpen.wait(true);
+
+        ctx.r3.u32 = 0;
+
+        return;
+    }
+
+    ctx.r3.u32 = 1;
+}
+
 // SWA::CTitleStateIntro::Update
 PPC_FUNC_IMPL(__imp__sub_82587E50);
 PPC_FUNC(sub_82587E50)
@@ -47,7 +97,7 @@ PPC_FUNC(sub_82587E50)
     {
         __imp__sub_82587E50(ctx, base);
     }
-    else
+    else if (!ProcessCorruptSaveMessage())
     {
         auto pInputState = SWA::CInputState::GetInstance();
 

UnleashedRecomp/patches/ui/CTitleStateMenu_patches.cpp

@@ -56,6 +56,10 @@ PPC_FUNC(sub_825882B8)
     auto isOptionsIndex = pTitleState->m_pMember->m_pTitleMenu->m_CursorIndex == 2;
     auto isInstallIndex = pTitleState->m_pMember->m_pTitleMenu->m_CursorIndex == 3;
 
+    // Always default to New Game with corrupted save data.
+    if (App::s_isSaveDataCorrupt && pTitleState->m_pMember->m_pTitleMenu->m_CursorIndex == 1)
+        pTitleState->m_pMember->m_pTitleMenu->m_CursorIndex = 0;
+
     if (!OptionsMenu::s_isVisible && isOptionsIndex)
     {
         if (OptionsMenu::s_isRestartRequired)
@@ -92,6 +96,14 @@ PPC_FUNC(sub_825882B8)
     }
 }
 
+void TitleMenuRemoveContinueOnCorruptSaveMidAsmHook(PPCRegister& r3)
+{
+    if (!App::s_isSaveDataCorrupt)
+        return;
+
+    r3.u64 = 0;
+}
+
 void TitleMenuRemoveStorageDeviceOptionMidAsmHook(PPCRegister& r11)
 {
     r11.u32 = 0;

UnleashedRecompLib/config/SWA.toml

@@ -663,3 +663,8 @@ registers = ["r3"]
 name = "InspireSubtitleMidAsmHook"
 address = 0x82B949B0
 registers = ["r3"]
+
+[[midasm_hook]]
+name = "TitleMenuRemoveContinueOnCorruptSaveMidAsmHook"
+address = 0x82585470
+registers = ["r3"]