From cc1112660a48de0ce372ca5e0f6fb65d50f75bcc Mon Sep 17 00:00:00 2001
From: Jeremy Smart <jeremy3141592@gmail.com>
Date: Fri, 11 Apr 2025 22:01:49 -0400
Subject: [PATCH] head: return to parse::<usize> and switch to
 parse_size_u64_max

---
 src/uu/head/src/parse.rs   | 17 +++++++++--------
 tests/by-util/test_head.rs | 28 ++++++++++------------------
 2 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/src/uu/head/src/parse.rs b/src/uu/head/src/parse.rs
index 0dbac6fe2..a4ce6e710 100644
--- a/src/uu/head/src/parse.rs
+++ b/src/uu/head/src/parse.rs
@@ -4,7 +4,7 @@
 // file that was distributed with this source code.
 
 use std::ffi::OsString;
-use uucore::parser::parse_size::{ParseSizeError, parse_size_u64};
+use uucore::parser::parse_size::{ParseSizeError, parse_size_u64_max};
 
 #[derive(PartialEq, Eq, Debug)]
 pub struct ParseError;
@@ -49,10 +49,11 @@ fn process_num_block(
     last_char: char,
     chars: &mut std::str::CharIndices,
 ) -> Option<Result<Vec<OsString>, ParseError>> {
-    let num = src.chars().fold(0u32, |acc, ch| {
-        acc.saturating_mul(10)
-            .saturating_add(ch.to_digit(10).unwrap())
-    });
+    let num = match src.parse::<usize>() {
+        Ok(n) => n,
+        Err(e) if *e.kind() == std::num::IntErrorKind::PosOverflow => usize::MAX,
+        _ => return Some(Err(ParseError)),
+    };
     let mut quiet = false;
     let mut verbose = false;
     let mut zero_terminated = false;
@@ -129,7 +130,7 @@ pub fn parse_num(src: &str) -> Result<(u64, bool), ParseSizeError> {
     if trimmed_string.is_empty() {
         Ok((0, all_but_last))
     } else {
-        parse_size_u64(trimmed_string).map(|n| (n, all_but_last))
+        parse_size_u64_max(trimmed_string).map(|n| (n, all_but_last))
     }
 }
 
@@ -193,11 +194,11 @@ mod tests {
     fn test_parse_obsolete_overflow_x64() {
         assert_eq!(
             obsolete("-1000000000000000m"),
-            obsolete_result(&["-c", "4294967295"])
+            obsolete_result(&["-c", "18446744073709551615"])
         );
         assert_eq!(
             obsolete("-10000000000000000000000"),
-            obsolete_result(&["-n", "4294967295"])
+            obsolete_result(&["-n", "18446744073709551615"])
         );
     }
 
diff --git a/tests/by-util/test_head.rs b/tests/by-util/test_head.rs
index 6c73936f3..9cd690c73 100644
--- a/tests/by-util/test_head.rs
+++ b/tests/by-util/test_head.rs
@@ -321,24 +321,20 @@ fn test_bad_utf8_lines() {
 fn test_head_invalid_num() {
     new_ucmd!()
         .args(&["-c", "1024R", "emptyfile.txt"])
-        .fails()
-        .stderr_is(
-            "head: invalid number of bytes: '1024R': Value too large for defined data type\n",
-        );
+        .succeeds()
+        .no_output();
     new_ucmd!()
         .args(&["-n", "1024R", "emptyfile.txt"])
-        .fails()
-        .stderr_is(
-            "head: invalid number of lines: '1024R': Value too large for defined data type\n",
-        );
+        .succeeds()
+        .no_output();
     new_ucmd!()
         .args(&["-c", "1Y", "emptyfile.txt"])
-        .fails()
-        .stderr_is("head: invalid number of bytes: '1Y': Value too large for defined data type\n");
+        .succeeds()
+        .no_output();
     new_ucmd!()
         .args(&["-n", "1Y", "emptyfile.txt"])
-        .fails()
-        .stderr_is("head: invalid number of lines: '1Y': Value too large for defined data type\n");
+        .succeeds()
+        .no_output();
     #[cfg(target_pointer_width = "32")]
     {
         let sizes = ["1000G", "10T"];
@@ -350,10 +346,7 @@ fn test_head_invalid_num() {
     {
         let sizes = ["-1000G", "-10T"];
         for size in &sizes {
-            new_ucmd!()
-                .args(&["-c", size])
-                .fails()
-                .stderr_is("head: out of range integral type conversion attempted: number of -bytes or -lines is too large\n");
+            new_ucmd!().args(&["-c", size]).succeeds().no_output();
         }
     }
     new_ucmd!()
@@ -778,8 +771,7 @@ fn test_value_too_large() {
 
     new_ucmd!()
         .args(&["-n", format!("{MAX}0").as_str(), "lorem_ipsum.txt"])
-        .fails()
-        .stderr_contains("Value too large for defined data type");
+        .succeeds();
 }
 
 #[test]