Test for infershape when using scan as a repeat until

theano/scan_module/tests/test_scan.py

@@ -2515,6 +2515,17 @@ class T_Scan(unittest.TestCase):
                 if isinstance(x.op, theano.scan_module.scan_op.Scan)]
         assert len(lssc) == 1
 
+    def test_while_infershape(self):
+        x = tensor.vector('x')
+        def lambda_fn(x_t):
+            return x_t + 1, theano.scan_module.until( x_t > 3)
+        o, _  = theano.scan(lambda_fn, x)
+
+        f = theano.function([x], o.shape[0], mode=mode_with_opt)
+        vx = numpy.zeros((50,), dtype = theano.config.floatX)
+        vx[23] = 4
+        out = f(vx)
+        assert out == 24
 
     def test_grad_multiple_seqs_different_nsteps(self):
         # Example provided Michael Forbes