Detect cases where `boolean_indexing_set_or_inc` does not apply

pytensor/tensor/rewriting/jax.py

@@ -20,9 +20,11 @@ def boolean_indexing_set_or_inc(fgraph, node):
     """
 
     op = node.op
-    x = node.inputs[0]
-    y = node.inputs[1]
-    cond = node.inputs[2]
+    [x, y, cond] = node.inputs
+
+    # This rewrite only works when `y` is a scalar, so it can broadcast to the shape of x[cond]
+    if y.type.ndim > 0:
+        return
 
     if not isinstance(cond, TensorVariable):
         return

tests/link/jax/test_subtensor.py

@@ -5,7 +5,10 @@ import pytensor.tensor as at
 from pytensor.configdefaults import config
 from pytensor.graph.fg import FunctionGraph
 from pytensor.tensor import subtensor as at_subtensor
-from pytensor.tensor.rewriting.jax import boolean_indexing_sum
+from pytensor.tensor.rewriting.jax import (
+    boolean_indexing_set_or_inc,
+    boolean_indexing_sum,
+)
 from tests.link.jax.test_basic import compare_jax_and_py
 
 
@@ -216,7 +219,7 @@ def test_jax_IncSubtensor_boolean_indexing_reexpressible():
 
     This test ensures that `AdvancedIncSubtensor` `Op`s with boolean indexing is
     replaced with an equivalent `Switch` `Op`, using the
-    `jax_boolean_indexing_set_of_inc` rewrite.
+    `boolean_indexing_set_of_inc` rewrite.
 
     JAX forces users to re-express this logic manually, so this is an
     improvement over its user interface.
@@ -237,3 +240,12 @@ def test_jax_IncSubtensor_boolean_indexing_reexpressible():
     assert isinstance(out_at.owner.op, at_subtensor.AdvancedIncSubtensor)
     out_fg = FunctionGraph([x_at], [out_at])
     compare_jax_and_py(out_fg, [x_np])
+
+
+def test_boolean_indexing_set_or_inc_not_applicable():
+    """Test that `boolean_indexing_set_or_inc` does not return an invalid replacement in cases where it doesn't apply."""
+    x = at.vector("x")
+    mask = at.as_tensor(x) > 0
+    out = at_subtensor.set_subtensor(x[mask], [0, 1, 2])
+    fg = FunctionGraph([x], [out])
+    assert boolean_indexing_set_or_inc.transform(fg, fg.outputs[0].owner) is None