Auto merge of #43216 - steveklabnik:rollup, r=steveklabnik

Rollup of 7 pull requests

- Successful merges: #42926, #43125, #43157, #43167, #43187, #43203, #43204
- Failed merges:

3 files changed, 39 insertions, 22 deletions

diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index e7c7be981d2..3f466d5031e 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -2216,12 +2216,22 @@ impl Path {
     /// This function will traverse symbolic links to query information about the
     /// destination file. In case of broken symbolic links this will return `false`.
     ///
+    /// If you cannot access the directory containing the file, e.g. because of a
+    /// permission error, this will return `false`.
+    ///
     /// # Examples
     ///
     /// ```no_run
     /// use std::path::Path;
     /// assert_eq!(Path::new("does_not_exist.txt").exists(), false);
     /// ```
+    ///
+    /// # See Also
+    ///
+    /// This is a convenience function that coerces errors to false. If you want to
+    /// check errors, call [fs::metadata].
+    ///
+    /// [fs::metadata]: ../../std/fs/fn.metadata.html
     #[stable(feature = "path_ext", since = "1.5.0")]
     pub fn exists(&self) -> bool {
         fs::metadata(self).is_ok()
@@ -2232,6 +2242,9 @@ impl Path {
     /// This function will traverse symbolic links to query information about the
     /// destination file. In case of broken symbolic links this will return `false`.
     ///
+    /// If you cannot access the directory containing the file, e.g. because of a
+    /// permission error, this will return `false`.
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -2239,6 +2252,15 @@ impl Path {
     /// assert_eq!(Path::new("./is_a_directory/").is_file(), false);
     /// assert_eq!(Path::new("a_file.txt").is_file(), true);
     /// ```
+    ///
+    /// # See Also
+    ///
+    /// This is a convenience function that coerces errors to false. If you want to
+    /// check errors, call [fs::metadata] and handle its Result. Then call
+    /// [fs::Metadata::is_file] if it was Ok.
+    ///
+    /// [fs::metadata]: ../../std/fs/fn.metadata.html
+    /// [fs::Metadata::is_file]: ../../std/fs/struct.Metadata.html#method.is_file
     #[stable(feature = "path_ext", since = "1.5.0")]
     pub fn is_file(&self) -> bool {
         fs::metadata(self).map(|m| m.is_file()).unwrap_or(false)
@@ -2249,6 +2271,9 @@ impl Path {
     /// This function will traverse symbolic links to query information about the
     /// destination file. In case of broken symbolic links this will return `false`.
     ///
+    /// If you cannot access the directory containing the file, e.g. because of a
+    /// permission error, this will return `false`.
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -2256,6 +2281,15 @@ impl Path {
     /// assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
     /// assert_eq!(Path::new("a_file.txt").is_dir(), false);
     /// ```
+    ///
+    /// # See Also
+    ///
+    /// This is a convenience function that coerces errors to false. If you want to
+    /// check errors, call [fs::metadata] and handle its Result. Then call
+    /// [fs::Metadata::is_dir] if it was Ok.
+    ///
+    /// [fs::metadata]: ../../std/fs/fn.metadata.html
+    /// [fs::Metadata::is_dir]: ../../std/fs/struct.Metadata.html#method.is_dir
     #[stable(feature = "path_ext", since = "1.5.0")]
     pub fn is_dir(&self) -> bool {
         fs::metadata(self).map(|m| m.is_dir()).unwrap_or(false)
diff --git a/src/libstd/sys/redox/fs.rs b/src/libstd/sys/redox/fs.rs
index 87e50c40148..918893097f8 100644
--- a/src/libstd/sys/redox/fs.rs
+++ b/src/libstd/sys/redox/fs.rs
@@ -383,9 +383,10 @@ pub fn unlink(p: &Path) -> io::Result<()> {
     Ok(())
 }
 
-pub fn rename(_old: &Path, _new: &Path) -> io::Result<()> {
-    ::sys_common::util::dumb_print(format_args!("Rename\n"));
-    unimplemented!();
+pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
+    copy(old, new)?;
+    unlink(old)?;
+    Ok(())
 }
 
 pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
diff --git a/src/libstd/sys/redox/mod.rs b/src/libstd/sys/redox/mod.rs
index 31c40ea58b1..7c728ebb1af 100644
--- a/src/libstd/sys/redox/mod.rs
+++ b/src/libstd/sys/redox/mod.rs
@@ -39,25 +39,7 @@ pub mod thread_local;
 pub mod time;
 
 #[cfg(not(test))]
-pub fn init() {
-    use alloc::oom;
-
-    oom::set_oom_handler(oom_handler);
-
-    // A nicer handler for out-of-memory situations than the default one. This
-    // one prints a message to stderr before aborting. It is critical that this
-    // code does not allocate any memory since we are in an OOM situation. Any
-    // errors are ignored while printing since there's nothing we can do about
-    // them and we are about to exit anyways.
-    fn oom_handler() -> ! {
-        use intrinsics;
-        let msg = "fatal runtime error: out of memory\n";
-        unsafe {
-            let _ = syscall::write(2, msg.as_bytes());
-            intrinsics::abort();
-        }
-    }
-}
+pub fn init() {}
 
 pub fn decode_error_kind(errno: i32) -> ErrorKind {
     match errno {