Add --no-con to disable writing to CONOUT.

Fixes #7619

doc/man/wesnoth.6

@@ -193,6 +193,12 @@ if used) and exits
 .B --no-log-to-file
 prevents redirecting logged output to a file. Log files are created in the logs directory under the userdata folder.
 .TP
+.B --log-to-file
+log output is written to a file even if it would normally go to standard output/error. Cancels the effect of --no-log-to-file whether implicit or explicit.
+.TP
+.B --no-con
+For Windows, when used with --no-log-to-file, results in output being written to cerr/cout instead of CONOUT. Otherwise, does nothing.
+.TP
 .BI --max-fps \ fps
 the number of frames per second the game can show, the value should be between
 .B 1

src/commandline_options.cpp

@@ -254,6 +254,7 @@ commandline_options::commandline_options(const std::vector<std::string>& args)
 		("log-precise", "shows the timestamps in log output with more precision.")
 		("no-log-to-file", "log output is written to standard error rather than to a file.")
 		("log-to-file", "log output is written to a file even if it would normally go to standard output/error. Cancels the effect of --no-log-to-file whether implicit or explicit.")
+		("no-con", "For Windows, when used with --no-log-to-file, results in output being written to cerr/cout instead of CONOUT. Otherwise, does nothing.")
 		;
 
 	po::options_description multiplayer_opts("Multiplayer options");

src/log_windows.cpp

@@ -57,7 +57,7 @@ public:
 	console_handler(const console_handler&) = delete;
 	console_handler& operator=(const console_handler&) = delete;
 
-	console_handler();
+	console_handler(bool no_con);
 
 	/**
 	 * Returns whether we own the console we are attached to, if any.
@@ -70,10 +70,10 @@ private:
 	/**
 	 * Switches to using a native console.
 	 */
-	void enable_native_console_output();
+	void enable_native_console_output(bool no_con);
 };
 
-console_handler::console_handler()
+console_handler::console_handler(bool no_con)
 	: created_wincon_(false)
 {
 	DBG_LS << "Early init message";
@@ -84,7 +84,7 @@ console_handler::console_handler()
 		// already pointing to the console.
 		LOG_LS << "Console already attached at startup (built with console subsystem flag?), log file disabled.";
 	} else {
-		enable_native_console_output();
+		enable_native_console_output(no_con);
 	}
 
 	DBG_LS << "Windows console init complete!";
@@ -95,7 +95,7 @@ bool console_handler::owns_console() const
 	return created_wincon_;
 }
 
-void console_handler::enable_native_console_output()
+void console_handler::enable_native_console_output(bool no_con)
 {
 	if(AttachConsole(ATTACH_PARENT_PROCESS)) {
 		LOG_LS << "Attached parent process console.";
@@ -111,18 +111,20 @@ void console_handler::enable_native_console_output()
 		WRN_LS << "Cannot attach or allocate a console, continuing anyway (is this Wine?)";
 	}
 
-	DBG_LS << "stderr to console";
-	fflush(stderr);
-	std::cerr.flush();
-	assert(freopen("CONOUT$", "wb", stderr) == stderr);
+	if(!no_con) {
+		DBG_LS << "stderr to console";
+		fflush(stderr);
+		std::cerr.flush();
+		assert(freopen("CONOUT$", "wb", stderr) == stderr);
 
-	DBG_LS << "stdout to console";
-	fflush(stdout);
-	std::cout.flush();
-	assert(freopen("CONOUT$", "wb", stdout) == stdout);
+		DBG_LS << "stdout to console";
+		fflush(stdout);
+		std::cout.flush();
+		assert(freopen("CONOUT$", "wb", stdout) == stdout);
 
-	DBG_LS << "stdin from console";
-	assert(freopen("CONIN$",  "rb", stdin) == stdin);
+		DBG_LS << "stdin from console";
+		assert(freopen("CONIN$",  "rb", stdin) == stdin);
+	}
 
 	LOG_LS << "Console streams handover complete!";
 }
@@ -131,10 +133,10 @@ std::unique_ptr<console_handler> lfm;
 
 } // end anonymous namespace
 
-void do_console_redirect()
+void do_console_redirect(bool no_con)
 {
 	if(!lfm) {
-		lfm.reset(new console_handler());
+		lfm.reset(new console_handler(no_con));
 	}
 }
 

src/log_windows.hpp

@@ -50,7 +50,7 @@ namespace lg
  * horribly wrong as soon as we try to use the logging facilities internally
  * for debug messages.
  */
-void do_console_redirect();
+void do_console_redirect(bool no_con);
 
 /**
  * Returns true if a console was allocated by the Wesnoth process.

src/wesnoth.cpp

@@ -1060,6 +1060,8 @@ int main(int argc, char** argv)
 	// if false, output will be written to the terminal
 	// on windows, if wesnoth was not started from a console, then it will allocate one
 	bool write_to_log_file = true;
+	[[maybe_unused]]
+	bool no_con = false;
 
 	// --nobanner needs to be detected before the main command-line parsing happens
 	// --log-to needs to be detected so the logging output location is set before any actual logging happens
@@ -1110,6 +1112,10 @@ int main(int argc, char** argv)
 		} else if(arg == "--log-to-file") {
 			write_to_log_file = true;
 		}
+
+		if(arg == "--no-con") {
+			no_con = true;
+		}
 	}
 
 	// setup logging to file
@@ -1118,7 +1124,7 @@ int main(int argc, char** argv)
 		lg::set_log_to_file();
 	} else {
 #ifdef _WIN32
-		lg::do_console_redirect();
+		lg::do_console_redirect(no_con);
 #endif
 	}