add unit test

Author: hkratz

src/test/ui/stdlib-unit-tests/remove-dir-all-deep.rs

@@ -0,0 +1,36 @@
+// run-pass
+
+use std::env::{current_dir, set_current_dir};
+use std::fs::{create_dir, remove_dir_all, File};
+use std::path::Path;
+
+pub fn main() {
+    let saved_cwd = current_dir().unwrap();
+    if !Path::exists(Path::new("tmpdir")) {
+        create_dir("tmpdir").unwrap();
+    }
+    set_current_dir("tmpdir").unwrap();
+    let depth = if cfg!(target_os = "linux") {
+        // Should work on all Linux filesystems.
+        4096
+    } else if cfg!(target_os = "macos") {
+        // On Macos increasing depth leads to a superlinear slowdown.
+        1024
+    } else if cfg!(unix) {
+        // Should be no problem on other UNIXes either.
+        1024
+    } else {
+        // "Safe" fallback for other platforms.
+        64
+    };
+    for _ in 0..depth {
+        if !Path::exists(Path::new("a")) {
+            create_dir("empty_dir").unwrap();
+            File::create("empty_file").unwrap();
+            create_dir("a").unwrap();
+        }
+        set_current_dir("a").unwrap();
+    }
+    set_current_dir(saved_cwd).unwrap();
+    remove_dir_all("tmpdir").unwrap();
+}