Merge pull request #3018 from Narasimha1997/fix-cp-recursion

Fix: Avoid infinite recursion when source and destinations are same while using `cp -R`

src/uu/cp/src/cp.rs

@@ -969,6 +969,16 @@ fn copy_directory(
         return copy_file(root, target, options, symlinked_files);
     }
 
+    // check if root is a prefix of target
+    if path_has_prefix(target, root)? {
+        return Err(format!(
+            "cannot copy a directory, {}, into itself, {}",
+            root.quote(),
+            target.quote()
+        )
+        .into());
+    }
+
     let current_dir =
         env::current_dir().unwrap_or_else(|e| crash!(1, "failed to get current directory {}", e));
 
@@ -1573,6 +1583,13 @@ pub fn paths_refer_to_same_file(p1: &Path, p2: &Path) -> io::Result<bool> {
     Ok(pathbuf1 == pathbuf2)
 }
 
+pub fn path_has_prefix(p1: &Path, p2: &Path) -> io::Result<bool> {
+    let pathbuf1 = canonicalize(p1, MissingHandling::Normal, ResolveMode::Logical)?;
+    let pathbuf2 = canonicalize(p2, MissingHandling::Normal, ResolveMode::Logical)?;
+
+    Ok(pathbuf1.starts_with(pathbuf2))
+}
+
 #[test]
 fn test_cp_localize_to_target() {
     assert!(

tests/by-util/test_cp.rs

@@ -1462,6 +1462,52 @@ fn test_cp_archive_on_nonexistent_file() {
             "cp: cannot stat 'nonexistent_file.txt': No such file or directory (os error 2)",
         );
 }
+
+#[test]
+fn test_dir_recursive_copy() {
+    let scene = TestScenario::new(util_name!());
+    let at = &scene.fixtures;
+
+    at.mkdir("parent1");
+    at.mkdir("parent2");
+    at.mkdir("parent1/child");
+    at.mkdir("parent2/child1");
+    at.mkdir("parent2/child1/child2");
+    at.mkdir("parent2/child1/child2/child3");
+
+    // case-1: copy parent1 -> parent1: should fail
+    scene
+        .ucmd()
+        .arg("-R")
+        .arg("parent1")
+        .arg("parent1")
+        .fails()
+        .stderr_contains("cannot copy a directory");
+    // case-2: copy parent1 -> parent1/child should fail
+    scene
+        .ucmd()
+        .arg("-R")
+        .arg("parent1")
+        .arg("parent1/child")
+        .fails()
+        .stderr_contains("cannot copy a directory");
+    // case-3: copy parent1/child -> parent2 should pass
+    scene
+        .ucmd()
+        .arg("-R")
+        .arg("parent1/child")
+        .arg("parent2")
+        .succeeds();
+    // case-4: copy parent2/child1/ -> parent2/child1/child2/child3
+    scene
+        .ucmd()
+        .arg("-R")
+        .arg("parent2/child1/")
+        .arg("parent2/child1/child2/child3")
+        .fails()
+        .stderr_contains("cannot copy a directory");
+}
+
 #[test]
 fn test_cp_dir_vs_file() {
     new_ucmd!()