fix: Properly project unordered column in parquet prefiltered

crates/polars-io/src/parquet/read/read_impl.rs

@@ -561,7 +561,7 @@ fn rg_to_dfs_prefiltered(
                 hive::merge_sorted_to_schema_order(
                     &mut dead_columns.into_iter(), // df_columns
                     &mut live_columns.into_iter().skip(row_index.is_some() as usize), // hive_columns
-                    schema,
+                    &schema.try_project_indices(projection).unwrap(),
                     &mut merged,
                 );
 

py-polars/tests/unit/io/test_parquet.py

@@ -2588,4 +2588,28 @@ def test_utf8_verification_with_slice_20174() -> None:
     )
 
     f.seek(0)
-    pl.scan_parquet(f).head(1).collect()
+    assert_frame_equal(
+        pl.scan_parquet(f).head(1).collect(),
+        pl.Series("s", ["a"]).to_frame(),
+    )
+
+
+def test_parquet_prefiltered_unordered_projection_20175() -> None:
+    df = pl.DataFrame(
+        [
+            pl.Series("a", [0], pl.Int64),
+            pl.Series("b", [0], pl.Int64),
+        ]
+    )
+
+    f = io.BytesIO()
+    df.write_parquet(f)
+
+    f.seek(0)
+    out = (
+        pl.scan_parquet(f, parallel="prefiltered")
+        .filter(pl.col.a >= 0)
+        .select(["b", "a"])
+        .collect()
+    )
+    assert out.schema == pl.Schema({"b": pl.Int64, "a": pl.Int64})