fix: Do not panic in strptime() if format ends with '%' (#21176)

pola-rs · Feb 11, 2025 · 0654544 · 0654544
1 parent c1e493a
commit 0654544
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Showing 2 changed files with 32 additions and 24 deletions.
diff --git a/crates/polars-time/src/chunkedarray/string/strptime.rs b/crates/polars-time/src/chunkedarray/string/strptime.rs
@@ -207,31 +207,34 @@ pub(super) fn fmt_len(fmt: &[u8]) -> Option<u16> {
 
     while let Some(&val) = iter.next() {
         match val {
-            b'%' => match iter.next().expect("invalid pattern") {
-                b'Y' => cnt += 4,
-                b'y' => cnt += 2,
-                b'd' => cnt += 2,
-                b'm' => cnt += 2,
-                b'b' => cnt += 3,
-                b'H' => cnt += 2,
-                b'M' => cnt += 2,
-                b'S' => cnt += 2,
-                b'9' => {
-                    cnt += 9;
-                    debug_assert_eq!(iter.next(), Some(&b'f'));
-                    return Some(cnt);
-                },
-                b'6' => {
-                    cnt += 6;
-                    debug_assert_eq!(iter.next(), Some(&b'f'));
-                    return Some(cnt);
-                },
-                b'3' => {
-                    cnt += 3;
-                    debug_assert_eq!(iter.next(), Some(&b'f'));
-                    return Some(cnt);
+            b'%' => match iter.next() {
+                Some(&next_val) => match next_val {
+                    b'Y' => cnt += 4,
+                    b'y' => cnt += 2,
+                    b'd' => cnt += 2,
+                    b'm' => cnt += 2,
+                    b'b' => cnt += 3,
+                    b'H' => cnt += 2,
+                    b'M' => cnt += 2,
+                    b'S' => cnt += 2,
+                    b'9' => {
+                        cnt += 9;
+                        debug_assert_eq!(iter.next(), Some(&b'f'));
+                        return Some(cnt);
+                    },
+                    b'6' => {
+                        cnt += 6;
+                        debug_assert_eq!(iter.next(), Some(&b'f'));
+                        return Some(cnt);
+                    },
+                    b'3' => {
+                        cnt += 3;
+                        debug_assert_eq!(iter.next(), Some(&b'f'));
+                        return Some(cnt);
+                    },
+                    _ => return None,
                 },
-                _ => return None,
+                None => return None,
             },
             _ => {
                 cnt += 1;

diff --git a/py-polars/tests/unit/operations/namespaces/test_strptime.py b/py-polars/tests/unit/operations/namespaces/test_strptime.py
@@ -755,3 +755,8 @@ def test_out_of_ns_range_no_tu_specified_13592() -> None:
         dtype=pl.Datetime("us"),
     )
     assert_series_equal(result, expected)
+
+
+def test_wrong_format_percent() -> None:
+    with pytest.raises(InvalidOperationError):
+        pl.Series(["2019-01-01"]).str.strptime(pl.Date, format="d%")