Bug #29570 original error lost in write_event on slave

- make sure error gets propagated to thd->net by calling print_error
- also print the full error message

sql/log_event.cc

@@ -6057,8 +6057,9 @@ int Rows_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 
       default:
 	slave_print_msg(ERROR_LEVEL, rli, thd->net.last_errno,
-                        "Error in %s event: row application failed",
-                        get_type_str());
+                        "Error in %s event: row application failed. %s",
+                        get_type_str(),
+                        thd->net.last_error ? thd->net.last_error : "");
 	thd->query_error= 1;
 	break;
       }
@@ -6079,9 +6080,10 @@ int Rows_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
   {                     /* error has occured during the transaction */
     slave_print_msg(ERROR_LEVEL, rli, thd->net.last_errno,
                     "Error in %s event: error during transaction execution "
-                    "on table %s.%s",
+                    "on table %s.%s. %s",
                     get_type_str(), table->s->db.str, 
-                    table->s->table_name.str);
+                    table->s->table_name.str,
+                    thd->net.last_error ? thd->net.last_error : "");
 
      /*
       If one day we honour --skip-slave-errors in row-based replication, and
@@ -6997,7 +6999,12 @@ replace_record(THD *thd, TABLE *table,
     }
     if ((keynum= table->file->get_dup_key(error)) < 0)
     {
-      /* We failed to retrieve the duplicate key */
+      table->file->print_error(error, MYF(0));
+      /*
+        We failed to retrieve the duplicate key
+        - either because the error was not "duplicate key" error
+        - or because the information which key is not available
+      */
       DBUG_RETURN(error);
     }