Upgrade tempfile to 3.3.0 am: 4578b5b3b3

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/tempfile/+/2421166

Change-Id: If394573a4b3432141e826ed2da80cdcc1bf1c593
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

16 files changed, 317 insertions, 108 deletions

diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
new file mode 100644
index 0000000..cabd9cd
--- /dev/null
+++ b/.cargo_vcs_info.json
@@ -0,0 +1,6 @@
+{
+  "git": {
+    "sha1": "1a40687e06eb656044e3d2dffa1379f04b3ef3fd"
+  },
+  "path_in_vcs": ""
+}
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..0d7c068
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,52 @@
+on: [push]
+name: CI
+jobs:
+  build_and_test:
+    name: OS Test
+    strategy:
+      matrix:
+        rust-version:
+          - nightly
+          - "1.40"
+        os:
+          - ubuntu-latest
+          - windows-latest
+          - macos-latest
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust-version }}
+          default: true
+      - name: Build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+      - name: Test
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+  wasm:
+    name: WASM Test Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly
+          default: true
+      - name: Install Cargo WASI
+        uses: actions-rs/cargo@v1
+        with:
+          command: install
+          args: cargo-wasi
+      - name: Build
+        uses: actions-rs/cargo@v1
+        with:
+          command: wasi
+          args: build --features nightly
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a9d37c5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+target
+Cargo.lock
diff --git a/Android.bp b/Android.bp
index 67fafd2..9b54b9a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -42,13 +42,13 @@ rust_library {
     host_supported: true,
     crate_name: "tempfile",
     cargo_env_compat: true,
-    cargo_pkg_version: "3.2.0",
+    cargo_pkg_version: "3.3.0",
     srcs: ["src/lib.rs"],
     edition: "2018",
     rustlibs: [
         "libcfg_if",
+        "libfastrand",
         "liblibc",
-        "librand",
         "libremove_dir_all",
     ],
     apex_available: [
diff --git a/Cargo.toml b/Cargo.toml
index 1f8e784..253f866 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,42 +1,43 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
-name = "tempfile"
-version = "3.2.0"
-authors = [
-  "Steven Allen <steven@stebalien.com>",
-  "The Rust Project Developers",
-  "Ashley Mannix <ashleymannix@live.com.au>",
-  "Jason White <jasonaw0@gmail.com>",
-]
-documentation = "https://docs.rs/tempfile"
 edition = "2018"
+name = "tempfile"
+version = "3.3.0"
+authors = ["Steven Allen <steven@stebalien.com>", "The Rust Project Developers", "Ashley Mannix <ashleymannix@live.com.au>", "Jason White <jasonaw0@gmail.com>"]
 exclude = ["/.travis.yml", "/appveyor.yml"]
+description = "A library for managing temporary files and directories."
 homepage = "http://stebalien.com/projects/tempfile-rs"
+documentation = "https://docs.rs/tempfile"
 keywords = ["tempfile", "tmpfile", "filesystem"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/Stebalien/tempfile"
-description = "A library for managing temporary files and directories."
-
-[dependencies]
-cfg-if = "1"
-rand = { version = "0.8", features = ["small_rng", "getrandom"], default_features = false }
-remove_dir_all = "0.5"
+[dependencies.cfg-if]
+version = "1"
 
-[target.'cfg(any(unix, target_os = "wasi"))'.dependencies]
-libc = "0.2.27"
+[dependencies.fastrand]
+version = "1.6.0"
 
-[target.'cfg(windows)'.dependencies.winapi]
+[dependencies.remove_dir_all]
+version = "0.5"
+[dev-dependencies.doc-comment]
 version = "0.3"
-features = [
-    "fileapi",
-    "handleapi",
-    "winbase",
-]
-
-[target.'cfg(target_os = "redox")'.dependencies]
-redox_syscall = "0.2"
-
-[dev-dependencies]
-doc-comment = "0.3"
 
 [features]
 nightly = []
+[target."cfg(any(unix, target_os = \"wasi\"))".dependencies.libc]
+version = "0.2.27"
+[target."cfg(target_os = \"redox\")".dependencies.redox_syscall]
+version = "0.2.9"
+[target."cfg(windows)".dependencies.winapi]
+version = "0.3"
+features = ["fileapi", "handleapi", "winbase"]
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
new file mode 100644
index 0000000..c5729c8
--- /dev/null
+++ b/Cargo.toml.orig
@@ -0,0 +1,42 @@
+[package]
+name = "tempfile"
+version = "3.3.0"
+authors = [
+  "Steven Allen <steven@stebalien.com>",
+  "The Rust Project Developers",
+  "Ashley Mannix <ashleymannix@live.com.au>",
+  "Jason White <jasonaw0@gmail.com>",
+]
+documentation = "https://docs.rs/tempfile"
+edition = "2018"
+exclude = ["/.travis.yml", "/appveyor.yml"]
+homepage = "http://stebalien.com/projects/tempfile-rs"
+keywords = ["tempfile", "tmpfile", "filesystem"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/Stebalien/tempfile"
+description = "A library for managing temporary files and directories."
+
+[dependencies]
+cfg-if = "1"
+fastrand = "1.6.0"
+remove_dir_all = "0.5"
+
+[target.'cfg(any(unix, target_os = "wasi"))'.dependencies]
+libc = "0.2.27"
+
+[target.'cfg(windows)'.dependencies.winapi]
+version = "0.3"
+features = [
+    "fileapi",
+    "handleapi",
+    "winbase",
+]
+
+[target.'cfg(target_os = "redox")'.dependencies]
+redox_syscall = "0.2.9"
+
+[dev-dependencies]
+doc-comment = "0.3"
+
+[features]
+nightly = []
diff --git a/METADATA b/METADATA
index fee7cae..92ec9f7 100644
--- a/METADATA
+++ b/METADATA
@@ -1,3 +1,7 @@
+# This project was upgraded with external_updater.
+# Usage: tools/external_updater/updater.sh update rust/crates/tempfile
+# For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md
+
 name: "tempfile"
 description: "A library for managing temporary files and directories."
 third_party {
@@ -7,14 +11,13 @@ third_party {
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/tempfile/tempfile-3.2.0.crate"
+    value: "https://static.crates.io/crates/tempfile/tempfile-3.3.0.crate"
   }
-  version: "3.2.0"
-  # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same.
+  version: "3.3.0"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2021
-    month: 10
-    day: 25
+    year: 2023
+    month: 2
+    day: 6
   }
 }
diff --git a/NEWS b/NEWS
index 6c83656..c284424 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,18 @@
+3.3.0
+=====
+
+Features:
+
+* Replace rand with fastrand for a significantly smaller dependency tree. Cryptographic randomness
+  isn't necessary for temporary file names, and isn't all that helpful either.
+* Add limited WASI support.
+* Add a function to extract the inner data from a `SpooledTempFile`.
+
+Bug Fixes:
+
+* Make it possible to persist unnamed temporary files on linux by removing the `O_EXCL` flag.
+* Fix redox minimum crate version.
+
 3.2.0
 =====
 
diff --git a/src/dir.rs b/src/dir.rs
index d630762..d5a944b 100644
--- a/src/dir.rs
+++ b/src/dir.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 use remove_dir_all::remove_dir_all;
+use std::mem;
 use std::path::{self, Path, PathBuf};
 use std::{fmt, fs, io};
 
@@ -192,7 +193,7 @@ pub fn tempdir_in<P: AsRef<Path>>(dir: P) -> io::Result<TempDir> {
 /// [`std::fs`]: http://doc.rust-lang.org/std/fs/index.html
 /// [`std::process::exit()`]: http://doc.rust-lang.org/std/process/fn.exit.html
 pub struct TempDir {
-    path: Option<PathBuf>,
+    path: Box<Path>,
 }
 
 impl TempDir {
@@ -292,7 +293,7 @@ impl TempDir {
     /// # }
     /// ```
     pub fn path(&self) -> &path::Path {
-        self.path.as_ref().unwrap()
+        self.path.as_ref()
     }
 
     /// Persist the temporary directory to disk, returning the [`PathBuf`] where it is located.
@@ -322,8 +323,13 @@ impl TempDir {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn into_path(mut self) -> PathBuf {
-        self.path.take().unwrap()
+    pub fn into_path(self) -> PathBuf {
+        // Prevent the Drop impl from being called.
+        let mut this = mem::ManuallyDrop::new(self);
+
+        // replace this.path with an empty Box, since an empty Box does not
+        // allocate any heap memory.
+        mem::replace(&mut this.path, PathBuf::new().into_boxed_path()).into()
     }
 
     /// Closes and removes the temporary directory, returning a `Result`.
@@ -369,8 +375,12 @@ impl TempDir {
     pub fn close(mut self) -> io::Result<()> {
         let result = remove_dir_all(self.path()).with_err_path(|| self.path());
 
-        // Prevent the Drop impl from removing the dir a second time.
-        self.path = None;
+        // Set self.path to empty Box to release the memory, since an empty
+        // Box does not allocate any heap memory.
+        self.path = PathBuf::new().into_boxed_path();
+
+        // Prevent the Drop impl from being called.
+        mem::forget(self);
 
         result
     }
@@ -392,15 +402,14 @@ impl fmt::Debug for TempDir {
 
 impl Drop for TempDir {
     fn drop(&mut self) {
-        // Path is `None` if `close()` or `into_path()` has been called.
-        if let Some(ref p) = self.path {
-            let _ = remove_dir_all(p);
-        }
+        let _ = remove_dir_all(self.path());
     }
 }
 
 pub(crate) fn create(path: PathBuf) -> io::Result<TempDir> {
     fs::create_dir(&path)
         .with_err_path(|| &path)
-        .map(|_| TempDir { path: Some(path) })
+        .map(|_| TempDir {
+            path: path.into_boxed_path(),
+        })
 }
diff --git a/src/file/imp/mod.rs b/src/file/imp/mod.rs
index ceb630e..fbb2bbf 100644
--- a/src/file/imp/mod.rs
+++ b/src/file/imp/mod.rs
@@ -1,4 +1,4 @@
-cfg_if! {
+cfg_if::cfg_if! {
     if #[cfg(any(unix, target_os = "redox", target_os = "wasi"))] {
         mod unix;
         pub use self::unix::*;
diff --git a/src/file/imp/unix.rs b/src/file/imp/unix.rs
index 89249fd..480743c 100644
--- a/src/file/imp/unix.rs
+++ b/src/file/imp/unix.rs
@@ -2,7 +2,7 @@ use std::env;
 use std::ffi::{CString, OsStr};
 use std::fs::{self, File, OpenOptions};
 use std::io;
-cfg_if! {
+cfg_if::cfg_if! {
     if #[cfg(not(target_os = "wasi"))] {
         use std::os::unix::ffi::OsStrExt;
         use std::os::unix::fs::{MetadataExt, OpenOptionsExt};
diff --git a/src/file/mod.rs b/src/file/mod.rs
index 31fdd4b..b859ced 100644
--- a/src/file/mod.rs
+++ b/src/file/mod.rs
@@ -138,7 +138,7 @@ impl error::Error for PathPersistError {
 ///
 /// When dropped, the temporary file is deleted.
 pub struct TempPath {
-    path: PathBuf,
+    path: Box<Path>,
 }
 
 impl TempPath {
@@ -176,8 +176,8 @@ impl TempPath {
     /// # }
     /// ```
     pub fn close(mut self) -> io::Result<()> {
-        let result = fs::remove_file(&self.path).with_err_path(|| &self.path);
-        self.path = PathBuf::new();
+        let result = fs::remove_file(&self.path).with_err_path(|| &*self.path);
+        self.path = PathBuf::new().into_boxed_path();
         mem::forget(self);
         result
     }
@@ -231,7 +231,7 @@ impl TempPath {
                 // Don't drop `self`. We don't want to try deleting the old
                 // temporary file path. (It'll fail, but the failure is never
                 // seen.)
-                self.path = PathBuf::new();
+                self.path = PathBuf::new().into_boxed_path();
                 mem::forget(self);
                 Ok(())
             }
@@ -293,7 +293,7 @@ impl TempPath {
                 // Don't drop `self`. We don't want to try deleting the old
                 // temporary file path. (It'll fail, but the failure is never
                 // seen.)
-                self.path = PathBuf::new();
+                self.path = PathBuf::new().into_boxed_path();
                 mem::forget(self);
                 Ok(())
             }
@@ -341,9 +341,9 @@ impl TempPath {
                 // Don't drop `self`. We don't want to try deleting the old
                 // temporary file path. (It'll fail, but the failure is never
                 // seen.)
-                let path = mem::replace(&mut self.path, PathBuf::new());
+                let path = mem::replace(&mut self.path, PathBuf::new().into_boxed_path());
                 mem::forget(self);
-                Ok(path)
+                Ok(path.into())
             }
             Err(e) => Err(PathPersistError {
                 error: e,
@@ -351,6 +351,18 @@ impl TempPath {
             }),
         }
     }
+
+    /// Create a new TempPath from an existing path. This can be done even if no
+    /// file exists at the given path.
+    ///
+    /// This is mostly useful for interacting with libraries and external
+    /// components that provide files to be consumed or expect a path with no
+    /// existing file to be given.
+    pub fn from_path(path: impl Into<PathBuf>) -> Self {
+        Self {
+            path: path.into().into_boxed_path(),
+        }
+    }
 }
 
 impl fmt::Debug for TempPath {
@@ -953,7 +965,9 @@ pub(crate) fn create_named(
     imp::create_named(&path, open_options)
         .with_err_path(|| path.clone())
         .map(|file| NamedTempFile {
-            path: TempPath { path },
+            path: TempPath {
+                path: path.into_boxed_path(),
+            },
             file,
         })
 }
diff --git a/src/lib.rs b/src/lib.rs
index d89798f..c38ca7b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27,6 +27,42 @@
 //! rely on file paths for _some_ operations. See the security documentation on
 //! the `NamedTempFile` type for more information.
 //!
+//! ## Early drop pitfall
+//!
+//! Because `TempDir` and `NamedTempFile` rely on their destructors for cleanup, this can lead
+//! to an unexpected early removal of the directory/file, usually when working with APIs which are
+//! generic over `AsRef<Path>`. Consider the following example:
+//!
+//! ```no_run
+//! # use tempfile::tempdir;
+//! # use std::io;
+//! # use std::process::Command;
+//! # fn main() {
+//! #     if let Err(_) = run() {
+//! #         ::std::process::exit(1);
+//! #     }
+//! # }
+//! # fn run() -> Result<(), io::Error> {
+//! // Create a directory inside of `std::env::temp_dir()`.
+//! let temp_dir = tempdir()?;
+//!
+//! // Spawn the `touch` command inside the temporary directory and collect the exit status
+//! // Note that `temp_dir` is **not** moved into `current_dir`, but passed as a reference
+//! let exit_status = Command::new("touch").arg("tmp").current_dir(&temp_dir).status()?;
+//! assert!(exit_status.success());
+//!
+//! # Ok(())
+//! # }
+//! ```
+//!
+//! This works because a reference to `temp_dir` is passed to `current_dir`, resulting in the
+//! destructor of `temp_dir` being run after the `Command` has finished execution. Moving the
+//! `TempDir` into the `current_dir` call would result in the `TempDir` being converted into
+//! an internal representation, with the original value being dropped and the directory thus
+//! being deleted, before the command can be executed.
+//!
+//! The `touch` command would fail with an `No such file or directory` error.
+//!
 //! ## Examples
 //!
 //! Create a temporary file and write some data into it:
@@ -127,15 +163,8 @@
 #![allow(clippy::redundant_field_names)]
 #![cfg_attr(feature = "nightly", feature(wasi_ext))]
 
-#[macro_use]
-extern crate cfg_if;
-
-#[cfg(doctest)]
-#[macro_use]
-extern crate doc_comment;
-
 #[cfg(doctest)]
-doctest!("../README.md");
+doc_comment::doctest!("../README.md");
 
 const NUM_RETRIES: u32 = 1 << 31;
 const NUM_RAND_CHARS: usize = 6;
diff --git a/src/spooled.rs b/src/spooled.rs
index e6f750e..ed6c16f 100644
--- a/src/spooled.rs
+++ b/src/spooled.rs
@@ -2,8 +2,9 @@ use crate::file::tempfile;
 use std::fs::File;
 use std::io::{self, Cursor, Read, Seek, SeekFrom, Write};
 
+/// A wrapper for the two states of a `SpooledTempFile`.
 #[derive(Debug)]
-enum SpooledInner {
+pub enum SpooledData {
     InMemory(Cursor<Vec<u8>>),
     OnDisk(File),
 }
@@ -15,7 +16,7 @@ enum SpooledInner {
 #[derive(Debug)]
 pub struct SpooledTempFile {
     max_size: usize,
-    inner: SpooledInner,
+    inner: SpooledData,
 }
 
 /// Create a new spooled temporary file.
@@ -66,15 +67,15 @@ impl SpooledTempFile {
     pub fn new(max_size: usize) -> SpooledTempFile {
         SpooledTempFile {
             max_size: max_size,
-            inner: SpooledInner::InMemory(Cursor::new(Vec::new())),
+            inner: SpooledData::InMemory(Cursor::new(Vec::new())),
         }
     }
 
     /// Returns true if the file has been rolled over to disk.
     pub fn is_rolled(&self) -> bool {
         match self.inner {
-            SpooledInner::InMemory(_) => false,
-            SpooledInner::OnDisk(_) => true,
+            SpooledData::InMemory(_) => false,
+            SpooledData::OnDisk(_) => true,
         }
     }
 
@@ -83,11 +84,11 @@ impl SpooledTempFile {
     pub fn roll(&mut self) -> io::Result<()> {
         if !self.is_rolled() {
             let mut file = tempfile()?;
-            if let SpooledInner::InMemory(ref mut cursor) = self.inner {
+            if let SpooledData::InMemory(ref mut cursor) = self.inner {
                 file.write_all(cursor.get_ref())?;
                 file.seek(SeekFrom::Start(cursor.position()))?;
             }
-            self.inner = SpooledInner::OnDisk(file);
+            self.inner = SpooledData::OnDisk(file);
         }
         Ok(())
     }
@@ -97,20 +98,25 @@ impl SpooledTempFile {
             self.roll()?; // does nothing if already rolled over
         }
         match self.inner {
-            SpooledInner::InMemory(ref mut cursor) => {
+            SpooledData::InMemory(ref mut cursor) => {
                 cursor.get_mut().resize(size as usize, 0);
                 Ok(())
             }
-            SpooledInner::OnDisk(ref mut file) => file.set_len(size),
+            SpooledData::OnDisk(ref mut file) => file.set_len(size),
         }
     }
+
+    /// Consumes and returns the inner `SpooledData` type.
+    pub fn into_inner(self) -> SpooledData {
+        self.inner
+    }
 }
 
 impl Read for SpooledTempFile {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         match self.inner {
-            SpooledInner::InMemory(ref mut cursor) => cursor.read(buf),
-            SpooledInner::OnDisk(ref mut file) => file.read(buf),
+            SpooledData::InMemory(ref mut cursor) => cursor.read(buf),
+            SpooledData::OnDisk(ref mut file) => file.read(buf),
         }
     }
 }
@@ -119,7 +125,7 @@ impl Write for SpooledTempFile {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         // roll over to file if necessary
         let mut rolling = false;
-        if let SpooledInner::InMemory(ref mut cursor) = self.inner {
+        if let SpooledData::InMemory(ref mut cursor) = self.inner {
             rolling = cursor.position() as usize + buf.len() > self.max_size;
         }
         if rolling {
@@ -128,16 +134,16 @@ impl Write for SpooledTempFile {
 
         // write the bytes
         match self.inner {
-            SpooledInner::InMemory(ref mut cursor) => cursor.write(buf),
-            SpooledInner::OnDisk(ref mut file) => file.write(buf),
+            SpooledData::InMemory(ref mut cursor) => cursor.write(buf),
+            SpooledData::OnDisk(ref mut file) => file.write(buf),
         }
     }
 
     #[inline]
     fn flush(&mut self) -> io::Result<()> {
         match self.inner {
-            SpooledInner::InMemory(ref mut cursor) => cursor.flush(),
-            SpooledInner::OnDisk(ref mut file) => file.flush(),
+            SpooledData::InMemory(ref mut cursor) => cursor.flush(),
+            SpooledData::OnDisk(ref mut file) => file.flush(),
         }
     }
 }
@@ -145,8 +151,8 @@ impl Write for SpooledTempFile {
 impl Seek for SpooledTempFile {
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
         match self.inner {
-            SpooledInner::InMemory(ref mut cursor) => cursor.seek(pos),
-            SpooledInner::OnDisk(ref mut file) => file.seek(pos),
+            SpooledData::InMemory(ref mut cursor) => cursor.seek(pos),
+            SpooledData::OnDisk(ref mut file) => file.seek(pos),
         }
     }
 }
diff --git a/src/util.rs b/src/util.rs
index 01beeed..8c91b9c 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -1,32 +1,17 @@
-use rand::{self, Rng, SeedableRng};
-use rand::{distributions::Alphanumeric, rngs::SmallRng};
+use fastrand;
 use std::ffi::{OsStr, OsString};
-use std::thread_local;
-use std::{
-    cell::UnsafeCell,
-    path::{Path, PathBuf},
-};
-use std::{io, str};
+use std::path::{Path, PathBuf};
+use std::{io, iter::repeat_with};
 
 use crate::error::IoResultExt;
 
-thread_local! {
-    static THREAD_RNG: UnsafeCell<SmallRng> = UnsafeCell::new(SmallRng::from_entropy());
-}
-
 fn tmpname(prefix: &OsStr, suffix: &OsStr, rand_len: usize) -> OsString {
     let mut buf = OsString::with_capacity(prefix.len() + suffix.len() + rand_len);
     buf.push(prefix);
-
-    // Push each character in one-by-one. Unfortunately, this is the only
-    // safe(ish) simple way to do this without allocating a temporary
-    // String/Vec.
-    THREAD_RNG.with(|rng| unsafe {
-        (&mut *rng.get())
-            .sample_iter(&Alphanumeric)
-            .take(rand_len)
-            .for_each(|b| buf.push(str::from_utf8_unchecked(&[b as u8])))
-    });
+    let mut char_buf = [0u8; 4];
+    for c in repeat_with(fastrand::alphanumeric).take(rand_len) {
+        buf.push(c.encode_utf8(&mut char_buf));
+    }
     buf.push(suffix);
     buf
 }
diff --git a/tests/namedtempfile.rs b/tests/namedtempfile.rs
index a489d56..d2c7da2 100644
--- a/tests/namedtempfile.rs
+++ b/tests/namedtempfile.rs
@@ -1,10 +1,11 @@
 #![deny(rust_2018_idioms)]
 
 use std::env;
+use std::ffi::{OsStr, OsString};
 use std::fs::File;
 use std::io::{Read, Seek, SeekFrom, Write};
-use std::path::Path;
-use tempfile::{Builder, NamedTempFile};
+use std::path::{Path, PathBuf};
+use tempfile::{tempdir, Builder, NamedTempFile, TempPath};
 
 fn exists<P: AsRef<Path>>(path: P) -> bool {
     std::fs::metadata(path.as_ref()).is_ok()
@@ -217,6 +218,50 @@ fn test_temppath_persist_noclobber() {
 }
 
 #[test]
+fn temp_path_from_existing() {
+    let tmp_dir = tempdir().unwrap();
+    let tmp_file_path_1 = tmp_dir.path().join("testfile1");
+    let tmp_file_path_2 = tmp_dir.path().join("testfile2");
+
+    File::create(&tmp_file_path_1).unwrap();
+    assert!(tmp_file_path_1.exists(), "Test file 1 hasn't been created");
+
+    File::create(&tmp_file_path_2).unwrap();
+    assert!(tmp_file_path_2.exists(), "Test file 2 hasn't been created");
+
+    let tmp_path = TempPath::from_path(&tmp_file_path_1);
+    assert!(
+        tmp_file_path_1.exists(),
+        "Test file has been deleted before dropping TempPath"
+    );
+
+    drop(tmp_path);
+    assert!(
+        !tmp_file_path_1.exists(),
+        "Test file exists after dropping TempPath"
+    );
+    assert!(
+        tmp_file_path_2.exists(),
+        "Test file 2 has been deleted before dropping TempDir"
+    );
+}
+
+#[test]
+#[allow(unreachable_code)]
+fn temp_path_from_argument_types() {
+    // This just has to compile
+    return;
+
+    TempPath::from_path("");
+    TempPath::from_path(String::new());
+    TempPath::from_path(OsStr::new(""));
+    TempPath::from_path(OsString::new());
+    TempPath::from_path(Path::new(""));
+    TempPath::from_path(PathBuf::new());
+    TempPath::from_path(PathBuf::new().into_boxed_path());
+}
+
+#[test]
 fn test_write_after_close() {
     let path = NamedTempFile::new().unwrap().into_temp_path();
     File::create(path).unwrap().write_all(b"test").unwrap();