From 2d4dfc3d7ddbb063f3d258f0b8359ef18ddbf2b3 Mon Sep 17 00:00:00 2001
From: Sylvestre Ledru <sylvestre@debian.org>
Date: Mon, 1 May 2023 10:54:14 +0200
Subject: [PATCH] cp: add support POSIXLY_CORRECT=1 when dealing with dangling
 links

GNU: tests/cp/thru-dangling.sh
---
 src/uu/cp/src/cp.rs      |  1 +
 tests/by-util/test_cp.rs | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/uu/cp/src/cp.rs b/src/uu/cp/src/cp.rs
index 80540d222..3ccff0303 100644
--- a/src/uu/cp/src/cp.rs
+++ b/src/uu/cp/src/cp.rs
@@ -1498,6 +1498,7 @@ fn copy_file(
                 options.overwrite,
                 OverwriteMode::Clobber(ClobberMode::RemoveDestination)
             )
+            && std::env::var_os("POSIXLY_CORRECT").is_none()
         {
             return Err(Error::Error(format!(
                 "not writing through dangling symlink '{}'",
diff --git a/tests/by-util/test_cp.rs b/tests/by-util/test_cp.rs
index dfbbc1473..8c08d4c0a 100644
--- a/tests/by-util/test_cp.rs
+++ b/tests/by-util/test_cp.rs
@@ -1902,6 +1902,17 @@ fn test_copy_through_dangling_symlink() {
         .stderr_only("cp: not writing through dangling symlink 'target'\n");
 }
 
+#[test]
+fn test_copy_through_dangling_symlink_posixly_correct() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.touch("file");
+    at.symlink_file("nonexistent", "target");
+    ucmd.arg("file")
+        .arg("target")
+        .env("POSIXLY_CORRECT", "1")
+        .succeeds();
+}
+
 #[test]
 fn test_copy_through_dangling_symlink_no_dereference() {
     let (at, mut ucmd) = at_and_ucmd!();