From 8c86b83afb63c124a153f6f73c2fee87db37239b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Teemu=20P=C3=A4tsi?= <frendsick@gmail.com>
Date: Sat, 14 Jun 2025 22:23:17 +0300
Subject: [PATCH 1/2] uucore: format: Fix zero padding for hexadecimals

---
 .../src/lib/features/format/num_format.rs     | 41 +++++++------------
 1 file changed, 15 insertions(+), 26 deletions(-)

diff --git a/src/uucore/src/lib/features/format/num_format.rs b/src/uucore/src/lib/features/format/num_format.rs
index 12e19a095..52065c8b1 100644
--- a/src/uucore/src/lib/features/format/num_format.rs
+++ b/src/uucore/src/lib/features/format/num_format.rs
@@ -134,16 +134,14 @@ pub struct UnsignedInt {
 }
 
 impl Formatter<u64> for UnsignedInt {
-    fn fmt(&self, mut writer: impl Write, x: u64) -> std::io::Result<()> {
+    fn fmt(&self, writer: impl Write, x: u64) -> std::io::Result<()> {
         let mut s = match self.variant {
             UnsignedIntVariant::Decimal => format!("{x}"),
             UnsignedIntVariant::Octal(_) => format!("{x:o}"),
-            UnsignedIntVariant::Hexadecimal(Case::Lowercase, _) => {
-                format!("{x:x}")
-            }
-            UnsignedIntVariant::Hexadecimal(Case::Uppercase, _) => {
-                format!("{x:X}")
-            }
+            UnsignedIntVariant::Hexadecimal(case, _) => match case {
+                Case::Lowercase => format!("{x:x}"),
+                Case::Uppercase => format!("{x:X}"),
+            },
         };
 
         // Zeroes do not get a prefix. An octal value does also not get a
@@ -156,12 +154,7 @@ impl Formatter<u64> for UnsignedInt {
         };
 
         s = format!("{prefix}{s:0>width$}", width = self.precision);
-
-        match self.alignment {
-            NumberAlignment::Left => write!(writer, "{s:<width$}", width = self.width),
-            NumberAlignment::RightSpace => write!(writer, "{s:>width$}", width = self.width),
-            NumberAlignment::RightZero => write!(writer, "{s:0>width$}", width = self.width),
-        }
+        write_output(writer, "".to_string(), s, self.width, self.alignment)
     }
 
     fn try_from_spec(s: Spec) -> Result<Self, FormatError> {
@@ -700,7 +693,14 @@ fn write_output(
             }
         }
         NumberAlignment::RightZero => {
-            write!(writer, "{sign_indicator}{s:0>remaining_width$}")
+            // Add the padding after "0x" for hexadecimals
+            let (prefix, rest) = if s.len() >= 2 && s[..2].eq_ignore_ascii_case("0x") {
+                (&s[..2], &s[2..])
+            } else {
+                ("", s.as_str())
+            };
+            let remaining_width = remaining_width.saturating_sub(prefix.len());
+            write!(writer, "{sign_indicator}{prefix}{rest:0>remaining_width$}")
         }
     }
 }
@@ -1271,18 +1271,7 @@ mod test {
         assert_eq!(f("%#09.e", &(-100.0).into()), "-001.e+02");
         assert_eq!(f("%# 9.E", &100.0.into()), "   1.E+02");
         assert_eq!(f("% 12.2A", &(-100.0).into()), "  -0XC.80P+3");
-    }
-
-    #[test]
-    #[ignore = "Need issue #7510 to be fixed"]
-    fn format_float_others_broken() {
-        // TODO: Merge this back into format_float_others.
-        let f = |fmt_str: &str, n: &ExtendedBigDecimal| {
-            let format = Format::<Float, &ExtendedBigDecimal>::parse(fmt_str).unwrap();
-            fmt(&format, n)
-        };
-
-        // #7510
         assert_eq!(f("%012.2a", &(-100.0).into()), "-0x00c.80p+3");
+        assert_eq!(f("%012.2A", &(-100.0).into()), "-0X00C.80P+3");
     }
 }

From cf7255f0856afc80dd681658e393642459a1ad23 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Teemu=20P=C3=A4tsi?= <frendsick@gmail.com>
Date: Sun, 15 Jun 2025 00:26:29 +0300
Subject: [PATCH 2/2] printf: Test formatting hex with padding

---
 tests/by-util/test_printf.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/by-util/test_printf.rs b/tests/by-util/test_printf.rs
index c0e9c41b3..ef618d0c8 100644
--- a/tests/by-util/test_printf.rs
+++ b/tests/by-util/test_printf.rs
@@ -906,6 +906,10 @@ fn pad_unsigned_three() {
         ("%#.3x", "0x003"),
         ("%#.3X", "0X003"),
         ("%#.3o", "003"),
+        ("%#05x", "0x003"),
+        ("%#05X", "0X003"),
+        ("%3x", "  3"),
+        ("%3X", "  3"),
     ] {
         new_ucmd!()
             .args(&[format, "3"])