csplit: only allow ASCII digits for repeat pattern

src/uu/csplit/src/patterns.rs

@@ -107,7 +107,7 @@ fn extract_patterns(args: &[String]) -> Result<Vec<Pattern>, CsplitError> {
     let mut patterns = Vec::with_capacity(args.len());
     let to_match_reg =
         Regex::new(r"^(/(?P<UPTO>.+)/|%(?P<SKIPTO>.+)%)(?P<OFFSET>[\+-]?\d+)?$").unwrap();
-    let execute_ntimes_reg = Regex::new(r"^\{(?P<TIMES>\d+)|\*\}$").unwrap();
+    let execute_ntimes_reg = Regex::new(r"^\{(?P<TIMES>[0-9]+)|\*\}$").unwrap();
     let mut iter = args.iter().peekable();
 
     while let Some(arg) = iter.next() {

tests/by-util/test_csplit.rs

@@ -83,6 +83,15 @@ fn test_up_to_line_sequence() {
     assert_eq!(at.read("xx02"), generate(25, 51));
 }
 
+#[test]
+fn test_up_to_line_with_non_ascii_repeat() {
+    // we use a different error message than GNU
+    new_ucmd!()
+        .args(&["numbers50.txt", "10", "{𝟚}"])
+        .fails()
+        .stderr_contains("invalid pattern");
+}
+
 #[test]
 fn test_up_to_match() {
     let (at, mut ucmd) = at_and_ucmd!();