df: remove trailing spaces in rightmost column

src/uu/df/src/table.rs

@@ -432,12 +432,21 @@ impl fmt::Display for Table {
         while let Some(row) = row_iter.next() {
             let mut col_iter = row.iter().enumerate().peekable();
             while let Some((i, elem)) = col_iter.next() {
+                let is_last_col = col_iter.peek().is_none();
+
                 match self.alignments[i] {
-                    Alignment::Left => write!(f, "{:<width$}", elem, width = self.widths[i])?,
+                    Alignment::Left => {
+                        if is_last_col {
+                            // no trailing spaces in last column
+                            write!(f, "{}", elem)?;
+                        } else {
+                            write!(f, "{:<width$}", elem, width = self.widths[i])?;
+                        }
+                    }
                     Alignment::Right => write!(f, "{:>width$}", elem, width = self.widths[i])?,
                 }
 
-                if col_iter.peek().is_some() {
+                if !is_last_col {
                     // column separator
                     write!(f, " ")?;
                 }

tests/by-util/test_df.rs

@@ -742,7 +742,7 @@ fn test_output_selects_columns() {
         .args(&["--output=source"])
         .succeeds()
         .stdout_move_str();
-    assert_eq!(output.lines().next().unwrap().trim_end(), "Filesystem");
+    assert_eq!(output.lines().next().unwrap(), "Filesystem");
 
     let output = new_ucmd!()
         .args(&["--output=source,target"])
@@ -801,7 +801,7 @@ fn test_output_file_all_filesystems() {
     let mut lines = output.lines();
     assert_eq!(lines.next().unwrap(), "File");
     for line in lines {
-        assert_eq!(line, "-   ");
+        assert_eq!(line, "-");
     }
 }
 
@@ -821,7 +821,7 @@ fn test_output_file_specific_files() {
         .succeeds()
         .stdout_move_str();
     let actual: Vec<&str> = output.lines().collect();
-    assert_eq!(actual, vec!["File", "a   ", "b   ", "c   "]);
+    assert_eq!(actual, vec!["File", "a", "b", "c"]);
 }
 
 #[test]
@@ -858,5 +858,5 @@ fn test_nonexistent_file() {
         .args(&["--output=file", "does-not-exist", "."])
         .fails()
         .stderr_is("df: does-not-exist: No such file or directory\n")
-        .stdout_is("File\n.   \n");
+        .stdout_is("File\n.\n");
 }