fix: Fix oob of join with literals and empty table (#17047)

crates/polars-ops/src/frame/join/mod.rs

@@ -93,10 +93,6 @@ pub trait DataFrameJoinOps: IntoDf {
         S: AsRef<str>,
     {
         let df_left = self.to_df();
-        #[cfg(feature = "cross_join")]
-        if let JoinType::Cross = args.how {
-            return df_left.cross_join(other, args.suffix.as_deref(), None);
-        }
         let selected_left = df_left.select_series(left_on)?;
         let selected_right = other.select_series(right_on)?;
         self._join_impl(other, selected_left, selected_right, args, true, false)
@@ -115,14 +111,30 @@ pub trait DataFrameJoinOps: IntoDf {
         _verbose: bool,
     ) -> PolarsResult<DataFrame> {
         let left_df = self.to_df();
-        let should_coalesce = args.coalesce.coalesce(&args.how);
-        assert_eq!(selected_left.len(), selected_right.len());
 
         #[cfg(feature = "cross_join")]
         if let JoinType::Cross = args.how {
             return left_df.cross_join(other, args.suffix.as_deref(), args.slice);
         }
 
+        // Clear literals if a frame is empty. Otherwise we could get an oob
+        fn clear(s: &mut [Series]) {
+            for s in s.iter_mut() {
+                if s.len() == 1 {
+                    *s = s.clear()
+                }
+            }
+        }
+        if left_df.is_empty() {
+            clear(&mut selected_left);
+        }
+        if other.is_empty() {
+            clear(&mut selected_right);
+        }
+
+        let should_coalesce = args.coalesce.coalesce(&args.how);
+        assert_eq!(selected_left.len(), selected_right.len());
+
         #[cfg(feature = "chunked_ids")]
         {
             // a left join create chunked-ids

crates/polars-pipe/src/executors/sinks/joins/row_values.rs

@@ -50,7 +50,10 @@ impl RowValues {
 
         for phys_e in self.join_column_eval.iter() {
             let s = phys_e.evaluate(chunk, &context.execution_state)?;
-            let s = s.to_physical_repr().rechunk();
+            let mut s = s.to_physical_repr().rechunk();
+            if chunk.data.is_empty() {
+                s = s.clear()
+            };
             if determine_idx {
                 names.push(s.name().to_string());
             }

py-polars/tests/unit/operations/test_join.py

@@ -973,3 +973,25 @@ def test_join_lit_panic_11410() -> None:
     assert symbols.join(dates, left_on=pl.lit(1), right_on=pl.lit(1)).drop(
         "literal"
     ).collect().to_dict(as_series=False) == {"symbol": [4], "date": [1]}
+
+
+def test_join_empty_literal_17027() -> None:
+    df1 = pl.DataFrame({"a": [1]})
+    df2 = pl.DataFrame(schema={"a": pl.Int64})
+
+    assert df1.join(df2, on=pl.lit(0), how="left").height == 1
+    assert df1.join(df2, on=pl.lit(0), how="inner").height == 0
+    assert (
+        df1.lazy()
+        .join(df2.lazy(), on=pl.lit(0), how="inner")
+        .collect(streaming=True)
+        .height
+        == 0
+    )
+    assert (
+        df1.lazy()
+        .join(df2.lazy(), on=pl.lit(0), how="left")
+        .collect(streaming=True)
+        .height
+        == 1
+    )