Handle zero-length iovecs in multicast messages

This commit was SVN r22507.

orte/mca/rmcast/tcp/rmcast_tcp.c

@@ -383,12 +383,14 @@ process:
                 ORTE_ERROR_LOG(rc);
                 goto cleanup;
             }
+            if (0 < tmp32) {
                 /* pack the bytes */
                 if (ORTE_SUCCESS != (rc = opal_dss.pack(&buf, snd->iovec_array[sz].iov_base, tmp32, OPAL_UINT8))) {
                     ORTE_ERROR_LOG(rc);
                     goto cleanup;
                 }
             }
+        }
         
     } else {
         /* flag it as being a buffer */
@@ -978,15 +980,18 @@ static void process_recv(int fd, short event, void *cbdata)
                         ORTE_ERROR_LOG(rc);
                         goto cleanup;
                     }
+                    iovec_array[i].iov_base = NULL;
+                    iovec_array[i].iov_len = sz;
+                    if (0 < sz) {
                         /* allocate the space */
                         iovec_array[i].iov_base = (uint8_t*)malloc(sz);
-                    iovec_array[i].iov_len = sz;
                         /* unpack the data */
                         if (ORTE_SUCCESS != (rc = opal_dss.unpack(buf, iovec_array[i].iov_base, &sz, OPAL_UINT8))) {
                             ORTE_ERROR_LOG(rc);
                             goto cleanup;
                         }                    
                     }
+                }
             } else if (1 == flag && NULL == recvd_buf) {
                 /* buffer was included */
                 recvd_buf = OBJ_NEW(opal_buffer_t);

orte/mca/rmcast/udp/rmcast_udp.c

@@ -872,15 +872,18 @@ static void process_recv(int fd, short event, void *cbdata)
                         ORTE_ERROR_LOG(rc);
                         goto cleanup;
                     }
+                    iovec_array[i].iov_base = NULL;
+                    iovec_array[i].iov_len = sz;
+                    if (0 < sz) {
                         /* allocate the space */
                         iovec_array[i].iov_base = (uint8_t*)malloc(sz);
-                    iovec_array[i].iov_len = sz;
                         /* unpack the data */
                         if (ORTE_SUCCESS != (rc = opal_dss.unpack(&buf, iovec_array[i].iov_base, &sz, OPAL_UINT8))) {
                             ORTE_ERROR_LOG(rc);
                             goto cleanup;
                         }                    
                     }
+                }
             } else if (1 == flag && NULL == recvd_buf) {
                 /* buffer was included */
                 recvd_buf = OBJ_NEW(opal_buffer_t);
@@ -1220,12 +1223,14 @@ static void xmit_data(int sd, short flags, void* send_req)
                     ORTE_ERROR_LOG(rc);
                     goto CLEANUP;
                 }
+                if (0 < tmp32) {
                     /* pack the bytes */
                     if (ORTE_SUCCESS != (rc = opal_dss.pack(&buf, snd->iovec_array[sz].iov_base, tmp32, OPAL_UINT8))) {
                         ORTE_ERROR_LOG(rc);
                         goto CLEANUP;
                     }
                 }
+            }
             
             /* unload the working buf to obtain the payload */
             if (ORTE_SUCCESS != (rc = opal_dss.unload(&buf, (void**)&bytes, &sz))) {