DolphinQt: Handle non-ASCII characters in Windows cmd arguments

CommandLineParse expects UTF-8 strings. (QApplication, on the
other hand, seems to be designed so that you can pass in the
char** argv untouched on Windows and get proper Unicode handling.)

Source/Core/Common/StringUtil.cpp

@@ -31,6 +31,7 @@
 
 #ifdef _WIN32
 #include <Windows.h>
+#include <shellapi.h>
 constexpr u32 CODEPAGE_SHIFT_JIS = 932;
 constexpr u32 CODEPAGE_WINDOWS_1252 = 1252;
 #else
@@ -630,3 +631,22 @@ std::string PathToString(const std::filesystem::path& path)
 #endif
 }
 #endif
+
+#ifdef _WIN32
+std::vector<std::string> CommandLineToUtf8Argv(const wchar_t* command_line)
+{
+  int nargs;
+  LPWSTR* tokenized = CommandLineToArgvW(command_line, &nargs);
+  if (!tokenized)
+    return {};
+
+  std::vector<std::string> argv(nargs);
+  for (size_t i = 0; i < nargs; ++i)
+  {
+    argv[i] = WStringToUTF8(tokenized[i]);
+  }
+
+  LocalFree(tokenized);
+  return argv;
+}
+#endif

Source/Core/Common/StringUtil.h

@@ -236,3 +236,7 @@ inline bool IsPrintableCharacter(char c)
 {
   return std::isprint(c, std::locale::classic());
 }
+
+#ifdef _WIN32
+std::vector<std::string> CommandLineToUtf8Argv(const wchar_t* command_line);
+#endif

Source/Core/DolphinQt/Main.cpp

@@ -3,6 +3,9 @@
 // Refer to the license.txt file included.
 
 #ifdef _WIN32
+#include <string>
+#include <vector>
+
 #include <Windows.h>
 #include <cstdio>
 #endif
@@ -101,6 +104,12 @@ static bool QtMsgAlertHandler(const char* caption, const char* text, bool yes_no
 int main(int argc, char* argv[])
 {
 #ifdef _WIN32
+  std::vector<std::string> utf8_args = CommandLineToUtf8Argv(GetCommandLineW());
+  const int utf8_argc = static_cast<int>(utf8_args.size());
+  std::vector<char*> utf8_argv(utf8_args.size());
+  for (size_t i = 0; i < utf8_args.size(); ++i)
+    utf8_argv[i] = utf8_args[i].data();
+
   const bool console_attached = AttachConsole(ATTACH_PARENT_PROCESS) != FALSE;
   HANDLE stdout_handle = ::GetStdHandle(STD_OUTPUT_HANDLE);
   if (console_attached && stdout_handle)
@@ -123,7 +132,12 @@ int main(int argc, char* argv[])
 #endif
 
   auto parser = CommandLineParse::CreateParser(CommandLineParse::ParserOptions::IncludeGUIOptions);
-  const optparse::Values& options = CommandLineParse::ParseArguments(parser.get(), argc, argv);
+  const optparse::Values& options =
+#ifdef _WIN32
+      CommandLineParse::ParseArguments(parser.get(), utf8_argc, utf8_argv.data());
+#else
+      CommandLineParse::ParseArguments(parser.get(), argc, argv);
+#endif
   const std::vector<std::string> args = parser->args();
 
   QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

Source/Core/WinUpdater/Main.cpp

@@ -16,26 +16,6 @@
 #include "UpdaterCommon/UI.h"
 #include "UpdaterCommon/UpdaterCommon.h"
 
-namespace
-{
-std::vector<std::string> CommandLineToUtf8Argv(PCWSTR command_line)
-{
-  int nargs;
-  LPWSTR* tokenized = CommandLineToArgvW(command_line, &nargs);
-  if (!tokenized)
-    return {};
-
-  std::vector<std::string> argv(nargs);
-  for (int i = 0; i < nargs; ++i)
-  {
-    argv[i] = WStringToUTF8(tokenized[i]);
-  }
-
-  LocalFree(tokenized);
-  return argv;
-}
-};  // namespace
-
 int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow)
 {
   if (lstrlenW(pCmdLine) == 0)