Index: src/event.cc
===================================================================
RCS file: /cvsroot/squid/squid3/src/event.cc,v
retrieving revision 1.5.12.2
diff -u -r1.5.12.2 event.cc
--- src/event.cc	16 Apr 2007 19:47:42 -0000	1.5.12.2
+++ src/event.cc	26 Jul 2007 15:28:25 -0000
@@ -305,8 +305,9 @@
 void
 EventScheduler::schedule(const char *name, EVH * func, void *arg, double when, int weight, bool cbdata)
 {
-
-    struct ev_entry *event = new ev_entry(name, func, arg, current_dtime + when, weight, cbdata);
+    // Treat when=0 events specially: many are async calls that preserve order
+    const double timestamp = when > 0.0 ? current_dtime + when : 0;
+    struct ev_entry *event = new ev_entry(name, func, arg, timestamp, weight, cbdata);
 
     struct ev_entry **E;
     debugs(41, 7, HERE << "schedule: Adding '" << name << "', in " << when << " seconds");