Fixed ByteStr not padding within its Display trait when no specific alignment is mentioned

library/core/src/bstr/mod.rs

@@ -174,39 +174,38 @@ impl fmt::Debug for ByteStr {
 #[unstable(feature = "bstr", issue = "134915")]
 impl fmt::Display for ByteStr {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fn fmt_nopad(this: &ByteStr, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-            for chunk in this.utf8_chunks() {
-                f.write_str(chunk.valid())?;
-                if !chunk.invalid().is_empty() {
-                    f.write_str("\u{FFFD}")?;
-                }
-            }
-            Ok(())
-        }
-
-        let Some(align) = f.align() else {
-            return fmt_nopad(self, f);
-        };
         let nchars: usize = self
             .utf8_chunks()
             .map(|chunk| {
                 chunk.valid().chars().count() + if chunk.invalid().is_empty() { 0 } else { 1 }
             })
             .sum();
+
         let padding = f.width().unwrap_or(0).saturating_sub(nchars);
         let fill = f.fill();
-        let (lpad, rpad) = match align {
-            fmt::Alignment::Left => (0, padding),
-            fmt::Alignment::Right => (padding, 0),
-            fmt::Alignment::Center => {
+
+        let (lpad, rpad) = match f.align() {
+            Some(fmt::Alignment::Right) => (padding, 0),
+            Some(fmt::Alignment::Center) => {
                 let half = padding / 2;
                 (half, half + padding % 2)
             }
+            // Either alignment is not specified or it's left aligned
+            // which behaves the same with padding
+            _ => (0, padding),
         };
+
         for _ in 0..lpad {
             write!(f, "{fill}")?;
         }
-        fmt_nopad(self, f)?;
+
+        for chunk in self.utf8_chunks() {
+            f.write_str(chunk.valid())?;
+            if !chunk.invalid().is_empty() {
+                f.write_str("\u{FFFD}")?;
+            }
+        }
+
         for _ in 0..rpad {
             write!(f, "{fill}")?;
         }

library/std/tests/path.rs

@@ -2291,6 +2291,26 @@ fn display_format_flags() {
     assert_eq!(format!("a{:#<5}b", Path::new("a").display()), "aa####b");
 }
 
+#[test]
+fn display_path_with_padding_no_align() {
+    assert_eq!(format!("{:10}", Path::new("/foo/bar").display()), "/foo/bar  ");
+}
+
+#[test]
+fn display_path_with_padding_align_left() {
+    assert_eq!(format!("{:<10}", Path::new("/foo/bar").display()), "/foo/bar  ");
+}
+
+#[test]
+fn display_path_with_padding_align_right() {
+    assert_eq!(format!("{:>10}", Path::new("/foo/bar").display()), "  /foo/bar");
+}
+
+#[test]
+fn display_path_with_padding_align_center() {
+    assert_eq!(format!("{:^10}", Path::new("/foo/bar").display()), " /foo/bar ");
+}
+
 #[test]
 fn into_rc() {
     let orig = "hello/world";