From 8b36ee182616019349652b493a9739f17d0231f0 Mon Sep 17 00:00:00 2001
From: sarankumar1325 <120080287+sarankumar1325@users.noreply.github.com>
Date: Sun, 25 Oct 2026 18:53:27 +0530
Subject: [PATCH] sort: don't rewrite a -t<chars> file operand after --

The `-t<chars>` to `--field-separator=<chars>` rewrite ran on every
argument, including file operands after `--`, so `sort -- -t=` tried to
use `=` as a separator instead of reading the file `-t=`. Stop the
rewrite once `--` has been seen, as in cut (#15806).
---
 src/uu/sort/src/sort.rs    | 9 +++++++++
 tests/by-util/test_sort.rs | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/uu/sort/src/sort.rs b/src/uu/sort/src/sort.rs
index 34a5bd6118..b8d8b10d03 100644
--- a/src/uu/sort/src/sort.rs
+++ b/src/uu/sort/src/sort.rs
@@ -2155,7 +2155,16 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     // https://github.com/uutils/coreutils/issues/2424#issuecomment-863825242,
     // and the same rewrite in `cut`), so rewrite every attached `-t<chars>`
     // argument to its long form, which preserves the separator verbatim.
+    // Arguments after `--` are file operands and must be left untouched.
+    let mut seen_double_dash = false;
     let args = args.into_iter().map(|x| {
+        if seen_double_dash {
+            return x;
+        }
+        if x == "--" {
+            seen_double_dash = true;
+            return x;
+        }
         // Non-UTF-8 separators are rejected later anyway, so lossy conversion
         // here only affects arguments that cannot become a valid separator.
         let as_str = x.to_string_lossy();
diff --git a/tests/by-util/test_sort.rs b/tests/by-util/test_sort.rs
index c309ad5b29..173938304b 100644
--- a/tests/by-util/test_sort.rs
+++ b/tests/by-util/test_sort.rs
@@ -2097,6 +2097,15 @@ fn test_separator_attached_equals() {
         .stdout_only("b=a=d\na=b=c\n");
 }
 
+#[test]
+fn test_separator_like_file_operand_after_double_dash() {
+    // After `--`, a file named `-t=` is an operand and must not be rewritten
+    // to `--field-separator==`.
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.write("-t=", "b\na\n");
+    ucmd.args(&["--", "-t="]).succeeds().stdout_only("a\nb\n");
+}
+
 #[test]
 fn test_separator_attached_equals_double() {
     // `-t==` selects the two-character separator `==`, which GNU rejects.