fix bug in predicate pushdown of binary predicate

polars/polars-lazy/src/logical_plan/lit.rs

@@ -122,6 +122,7 @@ make_literal!(u64, UInt64);
 
 /// The literal Null
 pub struct Null {}
+pub const NULL: Null = Null {};
 
 impl Literal for Null {
     fn lit(self) -> Expr {

polars/polars-lazy/src/tests/predicate_queries.rs

@@ -80,3 +80,19 @@ fn test_pass_unrelated_apply() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn filter_added_column_issue_2470() -> Result<()> {
+    let df = fruits_cars();
+
+    // the binary expression in the predicate lead to an incorrect pushdown because the rhs
+    // was not checked on the schema.
+    let out = df
+        .lazy()
+        .select([col("A"), lit(NULL).alias("foo")])
+        .filter(col("A").gt(lit(2i32)).and(col("foo").is_null()))
+        .collect()?;
+    assert_eq!(out.shape(), (3, 2));
+
+    Ok(())
+}

polars/polars-lazy/src/utils.rs

@@ -278,15 +278,9 @@ pub(crate) fn check_input_node(
     input_schema: &Schema,
     expr_arena: &Arena<AExpr>,
 ) -> bool {
-    // first determine output field, and then check if that output field could be selected
-    // on the input schema.
-    match expr_arena
-        .get(node)
-        .to_field(input_schema, Context::Default, expr_arena)
-    {
-        Ok(output_expr) => input_schema.field_with_name(output_expr.name()).is_ok(),
-        Err(_) => false,
-    }
+    aexpr_to_root_names(node, expr_arena)
+        .iter()
+        .all(|name| input_schema.index_of(name).is_ok())
 }
 
 pub(crate) fn aexprs_to_schema(