Output a log, savegame and screenshot on desync events

src/os/unix/crashlog_unix.cpp

@@ -517,6 +517,8 @@ class CrashLogUnix : public CrashLog {
 #endif
 
 public:
+	struct DesyncTag {};
+
 	/**
 	 * A crash log is always generated by signal.
 	 * @param signum the signal that was caused by the crash.
@@ -544,6 +546,15 @@ public:
 	{
 	}
 #endif /* WITH_SIGACTION */
+
+	CrashLogUnix(DesyncTag tag) : signum(0)
+	{
+#ifdef WITH_SIGACTION
+		this->si = nullptr;
+		this->context = nullptr;
+		this->signal_instruction_ptr_valid = false;
+#endif
+	}
 };
 
 /** The signals we want our crash handler to handle. */
@@ -608,3 +619,9 @@ static void CDECL HandleCrash(int signum)
 #endif
 	}
 }
+
+/* static */ void CrashLog::DesyncCrashLog()
+{
+	CrashLogUnix log(CrashLogUnix::DesyncTag{});
+	log.MakeDesyncCrashLog();
+}