Fix a bug in isometry.rs (#12469) (#12471)

* remove assertion * extend the test * add release notes * fix release notes * Update releasenotes/notes/fix-isometry-rust-adf0eed09c6611f1.yaml Co-authored-by: Matthew Treinish <mtreinish@kortar.org> --------- Co-authored-by: Matthew Treinish <mtreinish@kortar.org> (cherry picked from commit 0f0a634) Co-authored-by: Shelly Garion <46566946+ShellyGarion@users.noreply.github.com>
Qiskit · May 28, 2024 · bac400d · bac400d
1 parent 2a5c492
commit bac400d
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Showing 3 changed files with 8 additions and 4 deletions.
diff --git a/crates/accelerate/src/isometry.rs b/crates/accelerate/src/isometry.rs
@@ -212,7 +212,6 @@ fn construct_basis_states(
         } else if i == target_label {
             e2 += 1;
         } else {
-            assert!(j <= 1);
             e1 += state_free[j] as usize;
             e2 += state_free[j] as usize;
             j += 1

diff --git a/releasenotes/notes/fix-isometry-rust-adf0eed09c6611f1.yaml b/releasenotes/notes/fix-isometry-rust-adf0eed09c6611f1.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fix a bug in :class:`~.library.Isometry` due to an unnecessary assertion,
+    that led to an error in :meth:`.UnitaryGate.control`
+    when :class:`~.library.UnitaryGate` had more that two qubits.
diff --git a/test/python/circuit/test_controlled_gate.py b/test/python/circuit/test_controlled_gate.py
@@ -852,10 +852,9 @@ def test_controlled_unitary(self, num_ctrl_qubits):
         self.assertTrue(is_unitary_matrix(base_mat))
         self.assertTrue(matrix_equal(cop_mat, test_op.data))
 
-    @data(1, 2, 3, 4, 5)
-    def test_controlled_random_unitary(self, num_ctrl_qubits):
+    @combine(num_ctrl_qubits=(1, 2, 3, 4, 5), num_target=(2, 3))
+    def test_controlled_random_unitary(self, num_ctrl_qubits, num_target):
         """Test the matrix data of an Operator based on a random UnitaryGate."""
-        num_target = 2
         base_gate = random_unitary(2**num_target).to_instruction()
         base_mat = base_gate.to_matrix()
         cgate = base_gate.control(num_ctrl_qubits)