ob1: rewind convertor after failed send

This commit was SVN r26395.

ompi/mca/pml/ob1/pml_ob1_progress.c

@@ -53,6 +53,7 @@ int mca_pml_ob1_progress(void)
             completed_requests++;
             break;
         case MCA_PML_OB1_SEND_PENDING_START:
+            MCA_PML_OB1_SEND_REQUEST_RESET(sendreq);
             endpoint = sendreq->req_endpoint;
             send_succedded = false;
             for(j = 0; j < (int)mca_bml_base_btl_array_get_size(&endpoint->btl_eager); j++) {

ompi/mca/pml/ob1/pml_ob1_sendreq.c

@@ -70,7 +70,8 @@ void mca_pml_ob1_send_request_process_pending(mca_bml_base_btl_t *bml_btl)
                 add_request_to_send_pending(sendreq,
                         MCA_PML_OB1_SEND_PENDING_START, true);
             } else {
-                rc = mca_pml_ob1_send_request_start_btl(sendreq, send_dst);
+                 MCA_PML_OB1_SEND_REQUEST_RESET(sendreq);
+                 rc = mca_pml_ob1_send_request_start_btl(sendreq, send_dst);
                 if (OMPI_ERR_OUT_OF_RESOURCE == rc) {
                     /* No more resources on this btl so prepend to the pending
                      * list to minimize reordering and give up for now. */

ompi/mca/pml/ob1/pml_ob1_sendreq.h

@@ -159,6 +159,13 @@ get_request_from_send_pending(mca_pml_ob1_send_pending_t *type)
         (sendreq)->req_recv.pval = NULL;                                \
     }
 
+#define MCA_PML_OB1_SEND_REQUEST_RESET(sendreq)                             \
+{                                                                           \
+    size_t _position = 0;                                                   \
+    opal_convertor_set_position(&sendreq->req_send.req_base.req_convertor,  \
+                                &_position);                                \
+    assert( 0 == _position );                                               \
+}
 
 static inline void mca_pml_ob1_free_rdma_resources(mca_pml_ob1_send_request_t* sendreq)
 {