dont try and pack zero byte message

This commit was SVN r6532.

ompi/mca/pml/ob1/pml_ob1_recvreq.c

@@ -121,12 +121,20 @@ static void mca_pml_ob1_recv_request_ack(
     mca_pml_ob1_rendezvous_hdr_t* hdr)
 {
     mca_pml_ob1_proc_t* proc = recvreq->req_proc;
-    mca_pml_ob1_endpoint_t* ep = mca_pml_ob1_ep_array_get_next(&proc->btl_eager);
+    mca_pml_ob1_endpoint_t* ep;
     mca_btl_base_descriptor_t* des;
     mca_pml_ob1_recv_frag_t* frag;
     mca_pml_ob1_ack_hdr_t* ack;
     int rc;
 
+    /* if this hasn't been initialized yet - this is a synchronous send */
+    if(NULL == proc) {
+        ompi_proc_t *ompi_proc = ompi_comm_peer_lookup(
+                recvreq->req_recv.req_base.req_comm, hdr->hdr_match.hdr_src);
+        proc = recvreq->req_proc = ompi_proc->proc_pml;
+    }
+    ep = mca_pml_ob1_ep_array_get_next(&proc->btl_eager);
+    
     /* allocate descriptor */
     MCA_PML_OB1_ENDPOINT_DES_ALLOC(ep, des, sizeof(mca_pml_ob1_ack_hdr_t));
     if(NULL == des) {
@@ -145,6 +153,7 @@ static void mca_pml_ob1_recv_request_ack(
      * registered. if registered on both sides - do one rdma for
      * the entire message.
      */
+    if(hdr->hdr_match.hdr_msg_length > 0) {
 
         recvreq->req_chunk = mca_mpool_base_find(recvreq->req_recv.req_base.req_addr);
         if( NULL != recvreq->req_chunk &&
@@ -179,8 +188,14 @@ static void mca_pml_ob1_recv_request_ack(
                 recvreq->req_rdma_offset = recvreq->req_recv.req_bytes_packed;
                 ack->hdr_rdma_offset = recvreq->req_recv.req_bytes_packed;
             }
+        } else { 
+            recvreq->req_rdma_offset = hdr->hdr_frag_length;
+            ack->hdr_rdma_offset = hdr->hdr_frag_length;
         }
-    else{ 
+    }
+
+    /* zero byte message */
+    else { 
         recvreq->req_rdma_offset = hdr->hdr_frag_length;
         ack->hdr_rdma_offset = hdr->hdr_frag_length;
     }

ompi/mca/pml/ob1/pml_ob1_sendreq.c

@@ -301,7 +301,7 @@ int mca_pml_ob1_send_request_start(
 
             /* if the buffer is not pinned and leave pinned is false we eagerly send
                data to cover the cost of pinning the recv buffers on the peer */ 
-            if(NULL == sendreq->req_chunk && !mca_pml_ob1.leave_pinned){ 
+            if(size && NULL == sendreq->req_chunk && !mca_pml_ob1.leave_pinned){ 
                 /* pack the data into the supplied buffer */
                 iov.iov_base = (void*)((unsigned char*)segment->seg_addr.pval + 
                                        sizeof(mca_pml_ob1_rendezvous_hdr_t));