Try to do non-main thread crash save/screenshot in main thread

src/crashlog.cpp

@@ -78,6 +78,7 @@
 /* static */ const char *CrashLog::message = NULL;
 /* static */ char *CrashLog::gamelog_buffer = NULL;
 /* static */ const char *CrashLog::gamelog_last = NULL;
+/* static */ const CrashLog *CrashLog::main_thread_pending_crashlog = NULL;
 
 char *CrashLog::LogCompiler(char *buffer, const char *last) const
 {
@@ -534,8 +535,33 @@ bool CrashLog::MakeCrashLog() const
 		printf("Crash dump written to %s. Please add this file to any bug reports.\n\n", filename);
 	}
 
+	if (IsNonMainThread()) {
+		printf("Asking main thread to write crash savegame and screenshot...\n\n");
+		CrashLog::main_thread_pending_crashlog = this;
+		_exit_game = true;
+		CSleep(60000);
+		if (!CrashLog::main_thread_pending_crashlog) return ret;
+		printf("Main thread did not write crash savegame and screenshot within 60s, trying it from this thread...\n\n");
+	}
+	CrashLog::main_thread_pending_crashlog = nullptr;
+	bret = CrashLog::MakeCrashSavegameAndScreenshot();
+	if (!bret) ret = false;
+
+	return ret;
+}
+
+/**
+ * Makes a crash dump and crash savegame. It uses DEBUG to write
+ * information like paths to the console.
+ * @return true when everything is made successfully.
+ */
+bool CrashLog::MakeCrashSavegameAndScreenshot() const
+{
+	char filename[MAX_PATH];
+	bool ret = true;
+
 	printf("Writing crash savegame...\n");
-	bret = this->WriteSavegame(filename, lastof(filename));
+	bool bret = this->WriteSavegame(filename, lastof(filename));
 	if (bret) {
 		printf("Crash savegame written to %s. Please add this file and the last (auto)save to any bug reports.\n\n", filename);
 	} else {
@@ -555,6 +581,18 @@ bool CrashLog::MakeCrashLog() const
 	return ret;
 }
 
+/* static */ void CrashLog::MainThreadExitCheckPendingCrashlog()
+{
+	const CrashLog *cl = CrashLog::main_thread_pending_crashlog;
+	if (cl) {
+		CrashLog::main_thread_pending_crashlog = nullptr;
+		cl->MakeCrashSavegameAndScreenshot();
+
+		CrashLog::AfterCrashLogCleanup();
+		abort();
+	}
+}
+
 /**
  * Sets a message for the error message handler.
  * @param message The error message of the error.

src/crashlog.h

@@ -127,6 +127,7 @@ public:
 	bool WriteScreenshot(char *filename, const char *filename_last) const;
 
 	bool MakeCrashLog() const;
+	bool MakeCrashSavegameAndScreenshot() const;
 
 	/**
 	 * Initialiser for crash logs; do the appropriate things so crashes are
@@ -141,6 +142,10 @@ public:
 	inline const char *GetMessage() const { return this->message; }
 
 	static const char *GetAbortCrashlogReason();
+
+	static const CrashLog *main_thread_pending_crashlog;
+
+	static void MainThreadExitCheckPendingCrashlog();
 };
 
 #endif /* CRASHLOG_H */

src/openttd.cpp

@@ -890,6 +890,8 @@ int openttd_main(int argc, char *argv[])
 
 	VideoDriver::GetInstance()->MainLoop();
 
+	CrashLog::MainThreadExitCheckPendingCrashlog();
+
 	WaitTillSaved();
 
 	/* only save config if we have to */