paste: handle list ending with unescaped backslash

src/uu/paste/src/paste.rs

@@ -12,7 +12,7 @@ use std::fmt::Display;
 use std::fs::File;
 use std::io::{stdin, stdout, BufRead, BufReader, Read, Write};
 use std::path::Path;
-use uucore::error::{FromIo, UResult};
+use uucore::error::{FromIo, UResult, USimpleError};
 
 static ABOUT: &str = "Write lines consisting of the sequentially corresponding lines from each
 FILE, separated by TABs, to standard output.";
@@ -127,6 +127,16 @@ fn paste(
  files.push(file);
  }
 
+ if delimiters.ends_with('\\') && !delimiters.ends_with("\\\\") {
+ return Err(USimpleError::new(
+ 1,
+ format!(
+ "delimiter list ends with an unescaped backslash: {}",
+ delimiters
+ ),
+ ));
+ }
+
  let delimiters: Vec<char> = unescape(delimiters).chars().collect();
  let mut delim_count = 0;
  let mut delim_length = 1;
@@ -220,10 +230,8 @@ fn paste(
 }
 
 // Unescape all special characters
-// TODO: this will need work to conform to GNU implementation
 fn unescape(s: &str) -> String {
  s.replace("\\n", "\n")
  .replace("\\t", "\t")
  .replace("\\\\", "\\")
- .replace('\\', "")
 }

tests/by-util/test_paste.rs

@@ -156,6 +156,37 @@ fn test_multi_stdin() {
  }
 }
 
+#[test]
+fn test_delimiter_list_ending_with_escaped_backslash() {
+ for d in ["-d", "--delimiters"] {
+ let (at, mut ucmd) = at_and_ucmd!();
+ let mut ins = vec![];
+ for (i, _in) in ["a\n", "b\n"].iter().enumerate() {
+ let file = format!("in{}", i);
+ at.write(&file, _in);
+ ins.push(file);
+ }
+ ucmd.args(&[d, "\\\\"])
+ .args(&ins)
+ .succeeds()
+ .stdout_is("a\\b\n");
+ }
+}
+
+#[test]
+fn test_delimiter_list_ending_with_unescaped_backslash() {
+ for d in ["-d", "--delimiters"] {
+ new_ucmd!()
+ .args(&[d, "\\"])
+ .fails()
+ .stderr_contains("delimiter list ends with an unescaped backslash: \\");
+ new_ucmd!()
+ .args(&[d, "_\\"])
+ .fails()
+ .stderr_contains("delimiter list ends with an unescaped backslash: _\\");
+ }
+}
+
 #[test]
 fn test_data() {
  for example in EXAMPLE_DATA {