uucore/format: ignore the 0 flag if a precision is specified

src/uucore/src/lib/features/format/spec.rs

@@ -115,12 +115,6 @@ impl Spec {
             index += 1;
         }
 
-        let alignment = match (minus, zero) {
-            (true, _) => NumberAlignment::Left,
-            (false, true) => NumberAlignment::RightZero,
-            (false, false) => NumberAlignment::RightSpace,
-        };
-
         let positive_sign = match (plus, space) {
             (true, _) => PositiveSign::Plus,
             (false, true) => PositiveSign::Space,
@@ -136,6 +130,17 @@ impl Spec {
             None
         };
 
+        // The `0` flag is ignored if `-` is given or a precision is specified.
+        // So the only case for RightZero, is when `-` is not given and the
+        // precision is none.
+        let alignment = if minus {
+            NumberAlignment::Left
+        } else if zero && precision.is_none() {
+            NumberAlignment::RightZero
+        } else {
+            NumberAlignment::RightSpace
+        };
+
         // We ignore the length. It's not really relevant to printf
         let _ = Self::parse_length(rest, &mut index);
 

tests/by-util/test_csplit.rs

@@ -1357,3 +1357,18 @@ fn precision_format() {
     assert_eq!(at.read("xx   000"), generate(1, 10));
     assert_eq!(at.read("xx 0x001"), generate(10, 51));
 }
+
+#[test]
+fn precision_format2() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    ucmd.args(&["numbers50.txt", "10", "--suffix-format", "%0#6.3x"])
+        .succeeds()
+        .stdout_only("18\n123\n");
+
+    let count = glob(&at.plus_as_string("xx*"))
+        .expect("there should be splits created")
+        .count();
+    assert_eq!(count, 2);
+    assert_eq!(at.read("xx   000"), generate(1, 10));
+    assert_eq!(at.read("xx 0x001"), generate(10, 51));
+}