From 7d5da9eaeb47c12955d7ac823028e01b4a2df9fd Mon Sep 17 00:00:00 2001
From: PabloMK7 <hackyglitch2@gmail.com>
Date: Sun, 8 Mar 2026 18:41:31 +0100
Subject: [PATCH] core: Fix application jump parameters (#1845)

---
 src/core/hle/service/apt/applet_manager.cpp |  2 ++
 src/core/hle/service/apt/applet_manager.h   | 19 ++++++++++----
 src/core/hle/service/apt/apt.cpp            | 29 ++++++++++++---------
 3 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/src/core/hle/service/apt/applet_manager.cpp b/src/core/hle/service/apt/applet_manager.cpp
index 1dcbb430e..b459fdd1f 100644
--- a/src/core/hle/service/apt/applet_manager.cpp
+++ b/src/core/hle/service/apt/applet_manager.cpp
@@ -1456,6 +1456,8 @@ Result AppletManager::PrepareToStartApplication(u64 title_id, FS::MediaType medi
 
     capture_buffer_info.reset();
 
+    app_jump_parameters.Invalidate();
+
     return ResultSuccess;
 }
 
diff --git a/src/core/hle/service/apt/applet_manager.h b/src/core/hle/service/apt/applet_manager.h
index 3924ec510..0def102d3 100644
--- a/src/core/hle/service/apt/applet_manager.h
+++ b/src/core/hle/service/apt/applet_manager.h
@@ -185,12 +185,21 @@ private:
 using SysMenuArg = std::array<u8, SysMenuArgSize>;
 
 struct ApplicationJumpParameters {
-    u64 next_title_id;
-    FS::MediaType next_media_type;
-    ApplicationJumpFlags flags;
+    u64 next_title_id = ~0ULL;
+    FS::MediaType next_media_type{};
+    ApplicationJumpFlags flags{};
 
-    u64 current_title_id;
-    FS::MediaType current_media_type;
+    u64 current_title_id = ~0ULL;
+    FS::MediaType current_media_type{};
+
+    bool Valid() const {
+        return next_title_id != ~0ULL && current_title_id != ~0ULL;
+    }
+
+    void Invalidate() {
+        next_title_id = ~0ULL;
+        current_title_id = ~0ULL;
+    }
 
 private:
     template <class Archive>
diff --git a/src/core/hle/service/apt/apt.cpp b/src/core/hle/service/apt/apt.cpp
index 7b2dfeb19..50bb765a2 100644
--- a/src/core/hle/service/apt/apt.cpp
+++ b/src/core/hle/service/apt/apt.cpp
@@ -1251,23 +1251,26 @@ void Module::APTInterface::GetStartupArgument(Kernel::HLERequestContext& ctx) {
     bool exists = false;
 
     if (auto arg = apt->applet_manager->ReceiveDeliverArg()) {
-        param = std::move(arg->param);
-
         // TODO: This is a complete guess based on observations. It is unknown how the OtherMedia
         // type is handled and how it interacts with the OtherApp type, and it is unknown if
         // this (checking the jump parameters) is indeed the way the 3DS checks the types.
         const auto& jump_parameters = apt->applet_manager->GetApplicationJumpParameters();
-        switch (startup_argument_type) {
-        case StartupArgumentType::OtherApp:
-            exists = jump_parameters.current_title_id != jump_parameters.next_title_id &&
-                     jump_parameters.current_media_type == jump_parameters.next_media_type;
-            break;
-        case StartupArgumentType::Restart:
-            exists = jump_parameters.current_title_id == jump_parameters.next_title_id;
-            break;
-        case StartupArgumentType::OtherMedia:
-            exists = jump_parameters.current_media_type != jump_parameters.next_media_type;
-            break;
+
+        if (jump_parameters.Valid()) {
+            param = std::move(arg->param);
+
+            switch (startup_argument_type) {
+            case StartupArgumentType::OtherApp:
+                exists = jump_parameters.current_title_id != jump_parameters.next_title_id &&
+                         jump_parameters.current_media_type == jump_parameters.next_media_type;
+                break;
+            case StartupArgumentType::Restart:
+                exists = jump_parameters.current_title_id == jump_parameters.next_title_id;
+                break;
+            case StartupArgumentType::OtherMedia:
+                exists = jump_parameters.current_media_type != jump_parameters.next_media_type;
+                break;
+            }
         }
     }