From 49f8c96054dd734a859db29c2acd45af47764ac0 Mon Sep 17 00:00:00 2001
From: arbelonson-source <269032023+arbelonson-source@users.noreply.github.com>
Date: Mon, 31 Aug 2026 09:46:17 +0300
Subject: [PATCH] join: accept a hyphen-leading -t separator, quote it in the
 error

-t's value was rejected as an unrecognized flag when given as its own
argument (`join -t -x f1 f2`, not the attached `-tx` or `-t=x`): the
Arg was missing allow_hyphen_values, which every other option fixed
this way this session was too. GNU's own -t accepts any single
argument as the separator regardless of its first character.

Also quotes the value in the resulting "multi-character tab" message
to match GNU (`multi-character tab 'ab'`, not `multi-character tab
ab`) -- a separate, pre-existing bug in the same message that this
fix's own test would otherwise still fail against, since a
hyphen-leading multi-character value now reaches the exact same
message construction as any other one.

AI-assisted-by: Claude Opus 5, via Claude Code
---
 src/uu/join/locales/en-US.ftl |  2 +-
 src/uu/join/locales/fr-FR.ftl |  2 +-
 src/uu/join/src/join.rs       |  1 +
 tests/by-util/test_join.rs    | 16 +++++++++++++++-
 4 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/uu/join/locales/en-US.ftl b/src/uu/join/locales/en-US.ftl
index 04cc94fd013..c23cf02e897 100644
--- a/src/uu/join/locales/en-US.ftl
+++ b/src/uu/join/locales/en-US.ftl
@@ -24,7 +24,7 @@ join-help-z = line delimiter is NUL, not newline
 join-error-io = io error: { $error }
 join-error-non-utf8-tab = non-UTF-8 multi-byte tab
 join-error-unprintable-separators = unprintable field separators are only supported on unix-like platforms
-join-error-multi-character-tab = multi-character tab { $value }
+join-error-multi-character-tab = multi-character tab '{ $value }'
 join-error-both-files-stdin = both files cannot be standard input
 join-error-invalid-field-specifier = invalid field specifier: { $spec }
 join-error-invalid-file-number = invalid file number in field spec: { $spec }
diff --git a/src/uu/join/locales/fr-FR.ftl b/src/uu/join/locales/fr-FR.ftl
index eac430b5d55..7f947cf600e 100644
--- a/src/uu/join/locales/fr-FR.ftl
+++ b/src/uu/join/locales/fr-FR.ftl
@@ -24,7 +24,7 @@ join-help-z = le délimiteur de ligne est NUL, pas de nouvelle ligne
 join-error-io = erreur d'E/S : { $error }
 join-error-non-utf8-tab = tabulation multi-octets non-UTF-8
 join-error-unprintable-separators = les séparateurs de champs non imprimables ne sont pris en charge que sur les plateformes de type unix
-join-error-multi-character-tab = tabulation multi-caractères { $value }
+join-error-multi-character-tab = tabulation multi-caractères '{ $value }'
 join-error-both-files-stdin = les deux fichiers ne peuvent pas être l'entrée standard
 join-error-invalid-field-specifier = spécificateur de champ invalide : { $spec }
 join-error-invalid-file-number = numéro de fichier invalide dans la spécification de champ : { $spec }
diff --git a/src/uu/join/src/join.rs b/src/uu/join/src/join.rs
index 445e1641642..6b3188ed115 100644
--- a/src/uu/join/src/join.rs
+++ b/src/uu/join/src/join.rs
@@ -947,6 +947,7 @@ pub fn uu_app() -> Command {
                 .short('t')
                 .value_name("CHAR")
                 .value_parser(ValueParser::os_string())
+                .allow_hyphen_values(true)
                 .help(translate!("join-help-t")),
         )
         .arg(
diff --git a/tests/by-util/test_join.rs b/tests/by-util/test_join.rs
index a5ad3b619d6..51c9999820f 100644
--- a/tests/by-util/test_join.rs
+++ b/tests/by-util/test_join.rs
@@ -231,7 +231,21 @@ fn tab_multi_character() {
         .arg("-t")
         .arg("ab")
         .fails()
-        .stderr_is("join: multi-character tab ab\n");
+        .stderr_is("join: multi-character tab 'ab'\n");
+}
+
+#[test]
+fn tab_hyphen_leading_as_separate_arg() {
+    // A hyphen-leading separator value passed as its own argument (not
+    // attached with `-t-x`/`=`) must not be mistaken for a new,
+    // unrecognized flag.
+    new_ucmd!()
+        .arg("semicolon_fields_1.txt")
+        .arg("semicolon_fields_2.txt")
+        .arg("-t")
+        .arg("-x")
+        .fails()
+        .stderr_is("join: multi-character tab '-x'\n");
 }
 
 #[test]