Fix improper handling of BindingsArray in EstimatorPub.coerce (#11871)

(cherry picked from commit aba7c0f)

qiskit/primitives/containers/estimator_pub.py

@@ -141,7 +141,7 @@ def coerce(cls, pub: EstimatorPubLike, precision: float | None = None) -> Estima
 
         if len(pub) > 2 and pub[2] is not None:
             values = pub[2]
-            if not isinstance(values, Mapping):
+            if not isinstance(values, (BindingsArray, Mapping)):
                 values = {tuple(circuit.parameters): values}
             parameter_values = BindingsArray.coerce(values)
         else:

releasenotes/notes/fix-estimator-pub-coerce-5d13700e15126421.yaml

@@ -0,0 +1,7 @@
+---
+
+fixes:
+  - |
+    Fixed a bug where `qiskit.primitives.containers.estimator_pub.EstimatorPub.coerce()`
+    improperly handles the case where the third value is a `BindingsArray` instance, giving
+    rise to a ``ValueError`` whenever it is attempted.

test/python/primitives/containers/test_estimator_pub.py

@@ -182,6 +182,19 @@ def test_coerce_pub_with_precision(self, precision):
         pub2 = EstimatorPub.coerce(pub1, precision=precision)
         self.assertEqual(pub1, pub2)
 
+    def test_coerce_pub_with_exact_types(self):
+        """Test coercing an EstimatorPub"""
+        params = (Parameter("a"), Parameter("b"))
+        circuit = QuantumCircuit(2)
+        circuit.rx(params[0], 0)
+        circuit.ry(params[1], 1)
+        obs = ObservablesArray({"XY": 1})
+        params = BindingsArray(data={params: np.ones((10, 2))})
+        pub = EstimatorPub.coerce((circuit, obs, params))
+        self.assertIs(pub.circuit, circuit)
+        self.assertIs(pub.observables, obs)
+        self.assertIs(pub.parameter_values, params)
+
     @ddt.data(0.01, 0.02)
     def test_coerce_pub_without_shots(self, precision):
         """Test coercing an EstimatorPub"""