Disable render to main when using batch mode

https://bugs.dolphin-emu.org/issues/11888

This also includes another change: DolphinQt will now exit with an
error if you use --batch without specifying a game using any method
(unlike in the past where --batch would be ignored if you didn't
specify a game using --exec, even if you had used --nand-title).
The main reason why I did this was because coding the alternative
(ignoring --batch) would be annoying with render to main involved.

2 files changed, 28 insertions, 4 deletions

diff --git a/Source/Core/DolphinQt/Main.cpp b/Source/Core/DolphinQt/Main.cpp
index 65cbd0360d..b54caae0b8 100644
--- a/Source/Core/DolphinQt/Main.cpp
+++ b/Source/Core/DolphinQt/Main.cpp
@@ -138,7 +138,7 @@ int main(int argc, char* argv[])
   UICommon::CreateDirectories();
   UICommon::Init();
   Resources::Init();
-  Settings::Instance().SetBatchModeEnabled(options.is_set("batch") && options.is_set("exec"));
+  Settings::Instance().SetBatchModeEnabled(options.is_set("batch"));
 
   // Hook up alerts from core
   Common::RegisterMsgAlertHandler(QtMsgAlertHandler);
@@ -152,12 +152,14 @@ int main(int argc, char* argv[])
                    &app, &Core::HostDispatchJobs);
 
   std::unique_ptr<BootParameters> boot;
+  bool game_specified = false;
   if (options.is_set("exec"))
   {
     const std::list<std::string> paths_list = options.all("exec");
     const std::vector<std::string> paths{std::make_move_iterator(std::begin(paths_list)),
                                          std::make_move_iterator(std::end(paths_list))};
     boot = BootParameters::GenerateFromFile(paths);
+    game_specified = true;
   }
   else if (options.is_set("nand_title"))
   {
@@ -171,14 +173,30 @@ int main(int argc, char* argv[])
     {
       ModalMessageBox::critical(nullptr, QObject::tr("Error"), QObject::tr("Invalid title ID."));
     }
+    game_specified = true;
   }
   else if (!args.empty())
   {
     boot = BootParameters::GenerateFromFile(args.front());
+    game_specified = true;
   }
 
   int retval;
 
+  if (Settings::Instance().IsBatchModeEnabled() && !game_specified)
+  {
+    ModalMessageBox::critical(
+        nullptr, QObject::tr("Error"),
+        QObject::tr("Batch mode cannot be used without specifying a game to launch."));
+    retval = 1;
+  }
+  else if (Settings::Instance().IsBatchModeEnabled() && !boot)
+  {
+    // A game to launch was specified, but it was invalid.
+    // An error has already been shown by code above, so exit without showing another error.
+    retval = 1;
+  }
+  else
   {
     DolphinAnalytics::Instance().ReportDolphinStart("qt");
 
diff --git a/Source/Core/UICommon/CommandLineParse.cpp b/Source/Core/UICommon/CommandLineParse.cpp
index 0794546db5..bf3a556a29 100644
--- a/Source/Core/UICommon/CommandLineParse.cpp
+++ b/Source/Core/UICommon/CommandLineParse.cpp
@@ -22,7 +22,7 @@ class CommandLineConfigLayerLoader final : public Config::ConfigLayerLoader
 {
 public:
   CommandLineConfigLayerLoader(const std::list<std::string>& args, const std::string& video_backend,
-                               const std::string& audio_backend)
+                               const std::string& audio_backend, bool batch)
       : ConfigLayerLoader(Config::LayerType::CommandLine)
   {
     if (!video_backend.empty())
@@ -31,6 +31,11 @@ public:
     if (!audio_backend.empty())
       m_values.emplace_back(Config::MAIN_DSP_HLE.location, ValueToString(audio_backend == "HLE"));
 
+    // Batch mode hides the main window, and render to main hides the render window. To avoid a
+    // situation where we would have no window at all, disable render to main when using batch mode.
+    if (batch)
+      m_values.emplace_back(Config::MAIN_RENDER_TO_MAIN.location, ValueToString(false));
+
     // Arguments are in the format of <System>.<Section>.<Key>=Value
     for (const auto& arg : args)
     {
@@ -98,7 +103,7 @@ std::unique_ptr<optparse::OptionParser> CreateParser(ParserOptions options)
     parser->add_option("-l", "--logger").action("store_true").help("Open the logger");
     parser->add_option("-b", "--batch")
         .action("store_true")
-        .help("Run Dolphin without the user interface (Requires --exec)");
+        .help("Run Dolphin without the user interface (Requires --exec or --nand-title)");
     parser->add_option("-c", "--confirm").action("store_true").help("Set Confirm on Stop");
   }
 
@@ -120,7 +125,8 @@ static void AddConfigLayer(const optparse::Values& options)
 
   Config::AddLayer(std::make_unique<CommandLineConfigLayerLoader>(
       std::move(config_args), static_cast<const char*>(options.get("video_backend")),
-      static_cast<const char*>(options.get("audio_emulation"))));
+      static_cast<const char*>(options.get("audio_emulation")),
+      static_cast<bool>(options.get("batch"))));
 }
 
 optparse::Values& ParseArguments(optparse::OptionParser* parser, int argc, char** argv)