Ooops, I added another item to what I write to the buffer, but

forgot to make it big enough to hold the new item.  This was manifesting
itself as a crash on reset (if the ExternalPipe FDM was being used.)

src/FDM/ExternalPipe/ExternalPipe.cxx

@@ -44,7 +44,7 @@
 FGExternalPipe::FGExternalPipe( double dt, string name ) {
     valid = true;
 
-    buf = new char[sizeof(ctrls) + 1];
+    buf = new char[sizeof(char) + sizeof(int) + sizeof(ctrls)];
 
 #ifdef HAVE_MKFIFO
     fifo_name_1 = name + "1";