Try to make scope info logging more robust.

Add checks for validity of Vehicle ptrs in scope_dumper::VehicleInfo.
In Unix mode, try to handle SIGSEGVs when dumping scope info.

src/os/unix/crashlog_unix.cpp

@@ -251,6 +251,38 @@ class CrashLogUnix : public CrashLog {
 #endif
 		return buffer + seprintf(buffer, last, "\n");
 	}
+
+#if defined(USE_SCOPE_INFO) && defined(__GLIBC__)
+	/**
+	 * This is a wrapper around the generic LogScopeInfo function which sets
+	 * up a signal handler to catch any SIGSEGVs which may occur due to invalid data
+	 */
+	/* virtual */ char *LogScopeInfo(char *buffer, const char *last) const
+	{
+		logStacktraceSavedBuffer = buffer;
+
+		if (setjmp(logStacktraceJmpBuf) != 0) {
+			buffer = logStacktraceSavedBuffer;
+			buffer += seprintf(buffer, last, "\nSomething went seriously wrong when attempting to dump the scope info (SIGSEGV in signal handler).\n");
+			buffer += seprintf(buffer, last, "This is probably due to an invalid pointer or other corrupt data.\n\n");
+			return buffer;
+		}
+
+		signal(SIGSEGV, LogStacktraceSigSegvHandler);
+		sigset_t sigs;
+		sigset_t oldsigs;
+		sigemptyset(&sigs);
+		sigaddset(&sigs, SIGSEGV);
+		sigprocmask(SIG_UNBLOCK, &sigs, &oldsigs);
+
+		buffer = this->CrashLog::LogScopeInfo(buffer, last);
+
+		signal(SIGSEGV, SIG_DFL);
+		sigprocmask(SIG_SETMASK, &oldsigs, NULL);
+		return buffer;
+	}
+#endif
+
 public:
 	/**
 	 * A crash log is always generated by signal.