From da1ef4d2685c02e8320847d49a38726b2b6d52f0 Mon Sep 17 00:00:00 2001
From: Pieter Hintjens <ph@imatix.com>
Date: Sun, 8 May 2011 09:02:47 +0200
Subject: Fixed REP assert on missing envelope

Signed-off-by: Pieter Hintjens <ph@imatix.com>
---
 src/rep.cpp  | 34 ++++++++++++++++++++++++----------
 src/xrep.cpp | 13 ++++++++++++-
 src/xrep.hpp |  5 +++++
 3 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/src/rep.cpp b/src/rep.cpp
index ef0defc..8878bcd 100644
--- a/src/rep.cpp
+++ b/src/rep.cpp
@@ -67,24 +67,38 @@ int zmq::rep_t::xrecv (msg_t *msg_, int flags_)
     if (request_begins) {
 
         //  Copy the backtrace stack to the reply pipe.
-        bool bottom = false;
-        while (!bottom) {
+        while (true) {
 
-            //  TODO: What if request can be read but reply pipe is not
-            //  ready for writing?
+            //  TODO: If request can be read but reply pipe is not
+            //  ready for writing, we should drop the reply.
 
             //  Get next part of the backtrace stack.
             int rc = xrep_t::xrecv (msg_, flags_);
             if (rc != 0)
                 return rc;
-            zmq_assert (msg_->flags () & msg_t::more);
 
-            //  Empty message part delimits the traceback stack.
-            bottom = (msg_->size () == 0);
+            if (msg_->flags () & msg_t::more) {
 
-            //  Push it to the reply pipe.
-            rc = xrep_t::xsend (msg_, flags_);
-            zmq_assert (rc == 0);
+                //  Empty message part delimits the traceback stack.
+                bool bottom = (msg_->size () == 0);
+
+                //  Push it to the reply pipe.
+                rc = xrep_t::xsend (msg_, flags_);
+                zmq_assert (rc == 0);
+
+                //  The end of the traceback, move to processing message body.
+                if (bottom)
+                    break;
+            }
+            else {
+
+                //  If the traceback stack is malformed, discard anything
+                //  already sent to pipe (we're at end of invalid message)
+                //  and continue reading -- that'll switch us to the next pipe
+                //  and next request.
+                rc = xrep_t::rollback ();
+                zmq_assert (rc == 0);
+            }
         }
 
         request_begins = false;
diff --git a/src/xrep.cpp b/src/xrep.cpp
index 77481c3..f662aaf 100644
--- a/src/xrep.cpp
+++ b/src/xrep.cpp
@@ -61,7 +61,7 @@ void zmq::xrep_t::xattach_pipes (reader_t *inpipe_, writer_t *outpipe_,
 
         if (terminating) {
             register_term_acks (1);
-            outpipe_->terminate ();        
+            outpipe_->terminate ();
         }
     }
 
@@ -289,6 +289,17 @@ int zmq::xrep_t::xrecv (msg_t *msg_, int flags_)
     return -1;
 }
 
+int zmq::xrep_t::rollback (void)
+{
+    if (current_out) {
+        current_out->rollback ();
+        current_out = NULL;
+        more_out = false;
+    }
+    return 0;
+}
+
+
 bool zmq::xrep_t::xhas_in ()
 {
     //  There are subsequent parts of the partly-read message available.
diff --git a/src/xrep.hpp b/src/xrep.hpp
index 1c45655..7ca138c 100644
--- a/src/xrep.hpp
+++ b/src/xrep.hpp
@@ -51,6 +51,11 @@ namespace zmq
         bool xhas_in ();
         bool xhas_out ();
 
+    protected:
+
+        //  Rollback any message parts that were sent but not yet flushed.
+        int rollback ();
+
     private:
 
         //  Hook into the termination process.
-- 
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