tail: fix big number handling and error message quoting (#10155)

* tail: fix big number handling and error message quoting

* fix clippy: remove needless borrows in test_tail

Author: ChrisDryden

src/uu/tail/src/args.rs

@@ -13,7 +13,7 @@ use std::ffi::OsString;
 use std::io::IsTerminal;
 use std::time::Duration;
 use uucore::error::{UResult, USimpleError, UUsageError};
-use uucore::parser::parse_signed_num::{SignPrefix, parse_signed_num};
+use uucore::parser::parse_signed_num::{SignPrefix, parse_signed_num_max};
 use uucore::parser::parse_size::ParseSizeError;
 use uucore::parser::parse_time;
 use uucore::parser::shortcut_value_parser::ShortcutValueParser;
@@ -78,7 +78,7 @@ impl FilterMode {
                 Err(e) => {
                     return Err(USimpleError::new(
                         1,
-                        translate!("tail-error-invalid-number-of-bytes", "arg" => format!("'{e}'")),
+                        translate!("tail-error-invalid-number-of-bytes", "arg" => e.to_string()),
                     ));
                 }
             }
@@ -366,12 +366,6 @@ pub fn parse_obsolete(arg: &OsString, input: Option<&OsString>) -> UResult<Optio
             Err(USimpleError::new(
                 1,
                 match e {
-                    parse::ParseError::OutOfRange => {
-                        translate!("tail-error-invalid-number-out-of-range", "arg" => arg.quote())
-                    }
-                    parse::ParseError::Overflow => {
-                        translate!("tail-error-invalid-number-overflow", "arg" => arg.quote())
-                    }
                     // this ensures compatibility to GNU's error message (as tested in misc/tail)
                     parse::ParseError::Context => {
                         translate!(
@@ -389,7 +383,7 @@ pub fn parse_obsolete(arg: &OsString, input: Option<&OsString>) -> UResult<Optio
 }
 
 fn parse_num(src: &str) -> Result<Signum, ParseSizeError> {
-    let result = parse_signed_num(src)?;
+    let result = parse_signed_num_max(src)?;
     // tail: '+' means "starting from line/byte N", default/'-' means "last N"
     let is_plus = result.sign == Some(SignPrefix::Plus);
 

src/uu/tail/src/parse.rs

@@ -26,8 +26,6 @@ impl Default for ObsoleteArgs {
 
 #[derive(PartialEq, Eq, Debug)]
 pub enum ParseError {
-    OutOfRange,
-    Overflow,
     Context,
     InvalidEncoding,
 }
@@ -52,11 +50,7 @@ pub fn parse_obsolete(src: &OsString) -> Option<Result<ObsoleteArgs, ParseError>
         .unwrap_or(rest.len());
     let has_num = !rest[..end_num].is_empty();
     let num: u64 = if has_num {
-        if let Ok(num) = rest[..end_num].parse() {
-            num
-        } else {
-            return Some(Err(ParseError::OutOfRange));
-        }
+        rest[..end_num].parse().unwrap_or(u64::MAX)
     } else {
         10
     };
@@ -85,9 +79,7 @@ pub fn parse_obsolete(src: &OsString) -> Option<Result<ObsoleteArgs, ParseError>
     }
 
     let multiplier = if mode == 'b' { 512 } else { 1 };
-    let Some(num) = num.checked_mul(multiplier) else {
-        return Some(Err(ParseError::Overflow));
-    };
+    let num = num.saturating_mul(multiplier);
 
     Some(Ok(ObsoleteArgs {
         num,

tests/by-util/test_tail.rs

@@ -1155,23 +1155,63 @@ fn test_invalid_num() {
         .fails()
         .stderr_str()
         .starts_with("tail: invalid number of lines: '1024R'");
+    // 1Y overflows to u64::MAX (like GNU tail 9.9.x), so it succeeds
     new_ucmd!()
-        .args(&["-c", "1Y", "emptyfile.txt"])
-        .fails()
-        .stderr_str()
-        .starts_with("tail: invalid number of bytes: '1Y': Value too large for defined data type");
+        .args(&["-c", "1Y"])
+        .pipe_in("x")
+        .succeeds()
+        .stdout_is("x");
     new_ucmd!()
-        .args(&["-n", "1Y", "emptyfile.txt"])
-        .fails()
-        .stderr_str()
-        .starts_with("tail: invalid number of lines: '1Y': Value too large for defined data type");
+        .args(&["-n", "1Y"])
+        .pipe_in("x\n")
+        .succeeds()
+        .stdout_is("x\n");
     new_ucmd!()
         .args(&["-c", "-³"])
         .fails()
         .stderr_str()
         .starts_with("tail: invalid number of bytes: '³'");
 }
 
+#[test]
+fn test_oversized_num() {
+    const BIG: &str = "99999999999999999999999999999";
+    const DATA: &str = "abcd";
+    // -c <big> and -n <big>: output all (request more than available)
+    new_ucmd!()
+        .args(&["-c", BIG])
+        .pipe_in(DATA)
+        .succeeds()
+        .stdout_is(DATA);
+    new_ucmd!()
+        .args(&["-n", BIG])
+        .pipe_in("a\nb\n")
+        .succeeds()
+        .stdout_is("a\nb\n");
+    // +<big>: skip beyond input (empty output)
+    new_ucmd!()
+        .args(&["-c", &format!("+{BIG}")])
+        .pipe_in(DATA)
+        .succeeds()
+        .no_stdout();
+    new_ucmd!()
+        .args(&["-n", &format!("+{BIG}")])
+        .pipe_in("a\nb\n")
+        .succeeds()
+        .no_stdout();
+    // Obsolete syntax
+    new_ucmd!()
+        .arg(format!("+{BIG}c"))
+        .pipe_in(DATA)
+        .succeeds()
+        .no_stdout();
+    new_ucmd!()
+        .arg(format!("-{BIG}c"))
+        .pipe_in(DATA)
+        .succeeds()
+        .stdout_is(DATA);
+}
+
 #[test]
 fn test_num_with_undocumented_sign_bytes() {
     // tail: '-' is not documented (8.32 man pages)
@@ -4767,13 +4807,13 @@ fn test_gnu_args_err() {
         .fails_with_code(1)
         .no_stdout()
         .stderr_is("tail: option used in invalid context -- 2\n");
-    // err-5
+    // err-5: large numbers now clamp to u64::MAX
     scene
         .ucmd()
         .arg("-c99999999999999999999")
-        .fails_with_code(1)
-        .no_stdout()
-        .stderr_is("tail: invalid number of bytes: '99999999999999999999'\n");
+        .pipe_in("x")
+        .succeeds()
+        .stdout_is("x");
     // err-6
     scene
         .ucmd()
@@ -4787,20 +4827,19 @@ fn test_gnu_args_err() {
         .fails_with_code(1)
         .no_stdout()
         .stderr_is("tail: option used in invalid context -- 5\n");
+    // Large obsolete-syntax numbers clamp to u64::MAX
     scene
         .ucmd()
         .arg("-9999999999999999999b")
-        .fails_with_code(1)
-        .no_stdout()
-        .stderr_is("tail: invalid number: '-9999999999999999999b'\n");
+        .pipe_in("x")
+        .succeeds()
+        .stdout_is("x");
     scene
         .ucmd()
         .arg("-999999999999999999999b")
-        .fails_with_code(1)
-        .no_stdout()
-        .stderr_is(
-            "tail: invalid number: '-999999999999999999999b': Numerical result out of range\n",
-        );
+        .pipe_in("x")
+        .succeeds()
+        .stdout_is("x");
 }
 
 #[test]