Michael (I suspect Mark is in bed by now),

Is there any chance that the attached could be reviewed over the next 
few hours?

Daniel (who is off this week -> us long weekend) noted that the #ifdef vis:

+#ifdef __linux__
+  fetch_pid = TIDGET (inferior_ptid);
+  if (fetch_pid == 0)
+    fetch_pid = PIDGET (inferior_ptid);
+#else
+  fetch_pid = PIDGET (inferior_ptid);
+#endif

isn't needed.  The code should be unconditional.  I can fix/commit that 
provided the patch is ok.

It is effectively the last remaining fix for 5.3.

Andrew