[MXNET-749] Bug fixes in control flow operators

python/mxnet/symbol/contrib.py

@@ -486,12 +486,12 @@ def _union_inputs(*graphs):
         input_id_to_loc = {}    # Dict[int, int], given id(sym), input_id_to_loc maps it
                                 # to a `loc`, where inputs[loc] = sym
         for graph in graphs:
-            # input_syms: all inputs to the `graph`
-            name_to_input_syms = {sym.name: sym for sym in _get_graph_inputs(graph)}
             # some loop_vars are inputs to `graph`, some are not
             name_to_loop_vars = {sym.name: sym for sym in loop_vars}
             # other inputs to `graph` created by cut_graph
             name_to_cut_g_syms = {sym.list_outputs()[0]: sym for sym in _cut_subgraph(graph)}
+            # input_syms: all inputs to the `graph`
+            name_to_input_syms = {sym.name: sym for sym in _get_graph_inputs(graph)}
             # also we collect the mapping from var's name to var's loc in loop_vars
             name_to_var_locs = {sym.name: i for i, sym in enumerate(loop_vars)}
             # collect arguments for each subgraph
@@ -644,12 +644,12 @@ def _union_inputs(*graphs):
         input_id_to_loc = {}    # Dict[int, int], given id(sym), input_id_to_loc maps it
                                 # to a `loc`, where inputs[loc] = sym
         for graph in graphs:
-            # input_syms: all inputs to the `graph`
-            name_to_input_syms = {sym.name: sym for sym in _get_graph_inputs(graph)}
             # some input_vars are inputs to `graph`, some are not
             name_to_input_vars = {sym.name: sym for sym in inputs}
             # other inputs to `graph` created by cut_graph
             name_to_cut_g_syms = {sym.list_outputs()[0]: sym for sym in _cut_subgraph(graph)}
+            # input_syms: all inputs to the `graph`
+            name_to_input_syms = {sym.name: sym for sym in _get_graph_inputs(graph)}
             # collect arguments for each subgraph
             input_locs = []                         # results from the second step
             for name in graph.list_inputs():
@@ -696,5 +696,4 @@ def _union_inputs(*graphs):
         else_input_locs=else_input_locs,
         num_outputs=then_num_outputs
     )
-    result = _to_symbol_tuple(result, "result")
-    return list(result)
+    return [result[i] for i in range(then_num_outputs)]