Add check for duplicate names in import_graph_def (#9605)

tensorflow/python/framework/importer.py

@@ -275,6 +275,9 @@ def import_graph_def(graph_def, input_map=None, return_elements=None,
 
     # 1. Add operations without their inputs.
     for node in graph_def.node:
+      # Check to see if this op's name matches a previously seen op
+      if node.name in name_to_op:
+        raise ValueError('Duplicate name \'%s\' in GraphDef.' % node.name)
       # Set any default attr values that aren't present.
       if node.op not in op_dict:
         raise ValueError('No op named %s in defined operations.' % node.op)

tensorflow/python/framework/importer_test.py

@@ -685,6 +685,17 @@ class ImportGraphDefTest(test.TestCase):
       self.assertEqual("return_elements must be a list of strings.",
                        str(e.exception))
 
+  def testDuplicateOperationNames(self):
+    with ops.Graph().as_default():
+      with self.assertRaises(ValueError) as e:
+        importer.import_graph_def(
+            self._MakeGraphDef("""
+            node { name: 'A' op: 'Oi' }
+            node { name: 'B' op: 'Oi' }
+            node { name: 'A' op: 'Oi' }
+            """))
+      self.assertEqual("Duplicate name 'A' in GraphDef.", str(e.exception))
+
   def testWithExtensionAndAttr(self):
     with ops.Graph().as_default() as g:
       c = constant_op.constant(5.0, dtype=dtypes.float32, name="c")