From af01a4fcd414ddb67696f633bc7cfb67fb9f080e Mon Sep 17 00:00:00 2001
From: ragnarok-clanker <ragnarok-clanker>
Date: Sat, 31 Oct 2026 13:52:51 +0000
Subject: [PATCH] Decompile fn_24371 (ReplaceClientExecutable)

Batch #8061 by Yommy: 0 byte-identical, 1 confirmed by peer review.

- fn_24371 ReplaceClientExecutable: logic confirmed by peer review

Peer-reviewed-by: eAthena, secret
Accepted without human review: peers confirmed the logic ("same" ahead by at least 3, with 70% of the votes).
---
 Source/Client/Application/Launcher.cpp | 42 ++++++++++++++++++++++++++
 Source/Client/Application/Launcher.h   |  2 +-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Source/Client/Application/Launcher.cpp b/Source/Client/Application/Launcher.cpp
index 66a08c82..793c4e0b 100644
--- a/Source/Client/Application/Launcher.cpp
+++ b/Source/Client/Application/Launcher.cpp
@@ -10,6 +10,7 @@
 #include <string>
 #include <windows.h>
 #include <shellapi.h>
+#include <sys/stat.h>
 
 // STATIC: 0x0173ad64
 // GLOBAL: gl_24472
@@ -760,3 +761,44 @@ HANDLE StartClientProcess(char* program) {
   CreateProcessA(nullptr, commandLine, nullptr, nullptr, FALSE, 0, nullptr, nullptr, &startup, &process);
   return process.hProcess;
 }
+
+// OFFSET: 0x00E5C100
+// FUNCTION: fn_24371
+bool ReplaceClientExecutable(char* executable, const char* update) {
+  ApplyAiPatch();
+  if (_access(update, 0) != 0) {
+    return false;
+  }
+
+  const char* format;
+  if (g_serviceType == 12) {
+    const std::uint8_t messageSource[] = {0xBA, 0xB0, 0x67, 0xDB, 0x84, 0x2E, 0xC1, 0xFC, 0xF0, 0xA7, 0x2E, 0xDB, 0x82, 0x24, 0x80, 0xF5,
+                                          0xFE, 0xED, 0x67, 0xFE, 0x87, 0x2E, 0x90, 0xE4, 0xFA, 0xE3, 0x22, 0xD0, 0xCB, 0x08, 0x8A, 0xB1,
+                                          0xEF, 0xA2, 0x35, 0xDC, 0xCB, 0x24, 0x8E, 0xFF, 0xEB, 0xAA, 0x29, 0xC8, 0x8A, 0x35, 0xCF, 0x91};
+    thread_local EncryptedName<sizeof(messageSource), 0x91E147EBBD47C39FULL> message(messageSource);
+    format = message.Text();
+  } else {
+    const std::uint8_t messageSource[] = {0x24, 0x24, 0xB7, 0xB6, 0x60, 0xA5, 0x30, 0xB9, 0x60, 0x39, 0xF0, 0xBA, 0x77, 0xAB, 0x73, 0x81, 0x73, 0x32,
+                                          0xE4, 0xAC, 0x33, 0xEA, 0x38, 0xF1, 0x75, 0x38, 0xB7, 0xAD, 0x76, 0xF6, 0x27, 0xB0, 0x73, 0x23, 0x97};
+    thread_local EncryptedName<sizeof(messageSource), 0xD1538513DF975701ULL> message(messageSource);
+    format = message.Text();
+  }
+
+  char text[256];
+  std::sprintf(text, format, executable);
+
+  const std::uint8_t titleSource[] = {0x0C, 0x49, 0xFC, 0x3B, 0x27, 0x43};
+  thread_local EncryptedName<sizeof(titleSource), 0x078143534999254DULL> title(titleSource);
+  if (MessageBoxA(nullptr, text, title.Text(), MB_OKCANCEL | MB_ICONINFORMATION) != IDOK) {
+    return false;
+  }
+
+  _chmod(executable, _S_IWRITE);
+  _unlink(executable);
+  if (std::rename(update, executable) != 0) {
+    return false;
+  }
+
+  StartClientProcess(executable);
+  return true;
+}
diff --git a/Source/Client/Application/Launcher.h b/Source/Client/Application/Launcher.h
index 20912c71..7cef8eba 100644
--- a/Source/Client/Application/Launcher.h
+++ b/Source/Client/Application/Launcher.h
@@ -19,6 +19,6 @@ extern char g_launchAccountPassword[24];
 extern char g_launchAccountSex;
 extern bool g_launchPassCommandLine;
 
-HANDLE StartClientProcess(char* program);
+__declspec(noinline) HANDLE StartClientProcess(char* program);
 
 #endif