disable_eager_execution actually disables eager execution

This makes it somewhat less safe to call (as there can be eager tensorso out
there which will mess up graph building) but makes it do what it says on the
label.

PiperOrigin-RevId: 226947417

tensorflow/python/compat/BUILD

@@ -24,3 +24,14 @@ tf_py_test(
         "//tensorflow/python:client_testlib",
     ],
 )
+
+tf_py_test(
+    name = "disable_v2_behavior_test",
+    size = "small",
+    srcs = ["disable_v2_behavior_test.py"],
+    additional_deps = [
+        ":compat",
+        "//tensorflow/python:framework",
+        "//tensorflow/python:client_testlib",
+    ],
+)

tensorflow/python/compat/disable_v2_behavior_test.py

@@ -0,0 +1,39 @@
+# Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Tests for forward and backwards compatibility utilties."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorflow.python.compat import compat
+from tensorflow.python.framework import constant_op
+from tensorflow.python.framework import ops
+from tensorflow.python.platform import test
+
+
+class DisableV2BehaviorTest(test.TestCase):
+
+  def test_basic(self):
+    t = constant_op.constant([1, 2, 3])  # creates a hidden context
+    self.assertTrue(isinstance(t, ops.EagerTensor))
+    compat.disable_v2_behavior()
+    t = constant_op.constant([1, 2, 3])
+    self.assertFalse(isinstance(t, ops.EagerTensor))
+
+
+if __name__ == '__main__':
+  compat.enable_v2_behavior()
+  test.main()

tensorflow/python/framework/ops.py

@@ -5474,6 +5474,9 @@ def disable_eager_execution():
   projects from TensorFlow 1.x to 2.x.
   """
   context.default_execution_mode = context.GRAPH_MODE
+  c = context.context_safe()
+  if c is not None:
+    c._eager_context.is_eager = False  # pylint: disable=protected-access
 
 
 def enable_eager_execution_internal(config=None,