=== modified file 'src/helper.cc'
--- src/helper.cc	2012-11-24 14:30:02 +0000
+++ src/helper.cc	2012-12-04 14:17:59 +0000
@@ -866,42 +866,42 @@
         -- srv->stats.pending;
         ++ srv->stats.replies;
 
         ++ hlp->stats.replies;
 
         srv->answer_time = current_time;
 
         srv->dispatch_time = r->dispatch_time;
 
         hlp->stats.avg_svc_time =
             Math::intAverage(hlp->stats.avg_svc_time,
                              tvSubMsec(r->dispatch_time, current_time),
                              hlp->stats.replies, REDIRECT_AV_FACTOR);
 
         helperRequestFree(r);
     } else {
         debugs(84, DBG_IMPORTANT, "helperHandleRead: unexpected reply on channel " <<
                request_number << " from " << hlp->id_name << " #" << srv->index + 1 <<
                " '" << srv->rbuf << "'");
     }
-    srv->roffset -= (msg_end - srv->rbuf);
-    memmove(srv->rbuf, msg_end, srv->roffset + 1);
+    srv->roffset -= (msg_end - srv->rbuf + 1);
+    memmove(srv->rbuf, msg_end, srv->roffset);
 
     if (!srv->flags.shutdown) {
         helperKickQueue(hlp);
     } else if (!srv->flags.closing && !srv->stats.pending) {
         srv->flags.closing=1;
         srv->writePipe->close();
         return;
     }
 }
 
 static void
 helperHandleRead(const Comm::ConnectionPointer &conn, char *buf, size_t len, comm_err_t flag, int xerrno, void *data)
 {
     char *t = NULL;
     helper_server *srv = (helper_server *)data;
     helper *hlp = srv->parent;
     assert(cbdataReferenceValid(data));
 
     /* Bail out early on COMM_ERR_CLOSING - close handlers will tidy up for us */