Auto merge of #61296 - Centril:rollup-5ad68b0, r=Centril

Rollup of 9 pull requests

Successful merges:

 - #60742 (Allow const parameters in array sizes to be unified)
 - #60756 (Add better tests for hidden lifetimes in impl trait)
 - #60928 (Changes the type `mir::Mir` into `mir::Body`)
 - #61024 (tests: Centralize proc macros commonly used for testing)
 - #61157 (BufReader: In Seek impl, remove extra discard_buffer call)
 - #61195 (Special-case `.llvm` in mangler)
 - #61202 (Print PermissionExt::mode() in octal in Documentation Examples)
 - #61259 (Mailmap fixes)
 - #61273 (mention that MaybeUninit is a bit like Option)

Failed merges:

r? @ghost

3 files changed, 37 insertions, 2 deletions

diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs
index e309f81192c..d0e56acc8fb 100644
--- a/src/libstd/io/buffered.rs
+++ b/src/libstd/io/buffered.rs
@@ -1163,6 +1163,41 @@ mod tests {
     }
 
     #[test]
+    fn test_buffered_reader_seek_underflow_discard_buffer_between_seeks() {
+        // gimmick reader that returns Err after first seek
+        struct ErrAfterFirstSeekReader {
+            first_seek: bool,
+        }
+        impl Read for ErrAfterFirstSeekReader {
+            fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+                for x in &mut *buf {
+                    *x = 0;
+                }
+                Ok(buf.len())
+            }
+        }
+        impl Seek for ErrAfterFirstSeekReader {
+            fn seek(&mut self, _: SeekFrom) -> io::Result<u64> {
+                if self.first_seek {
+                    self.first_seek = false;
+                    Ok(0)
+                } else {
+                    Err(io::Error::new(io::ErrorKind::Other, "oh no!"))
+                }
+            }
+        }
+
+        let mut reader = BufReader::with_capacity(5, ErrAfterFirstSeekReader { first_seek: true });
+        assert_eq!(reader.fill_buf().ok(), Some(&[0, 0, 0, 0, 0][..]));
+
+        // The following seek will require two underlying seeks.  The first will
+        // succeed but the second will fail.  This should still invalidate the
+        // buffer.
+        assert!(reader.seek(SeekFrom::Current(i64::min_value())).is_err());
+        assert_eq!(reader.buffer().len(), 0);
+    }
+
+    #[test]
     fn test_buffered_writer() {
         let inner = Vec::new();
         let mut writer = BufWriter::with_capacity(2, inner);
diff --git a/src/libstd/sys/redox/ext/fs.rs b/src/libstd/sys/redox/ext/fs.rs
index 53b9dd68f73..4ddc1f09a31 100644
--- a/src/libstd/sys/redox/ext/fs.rs
+++ b/src/libstd/sys/redox/ext/fs.rs
@@ -27,7 +27,7 @@ pub trait PermissionsExt {
     ///     let metadata = f.metadata()?;
     ///     let permissions = metadata.permissions();
     ///
-    ///     println!("permissions: {}", permissions.mode());
+    ///     println!("permissions: {:o}", permissions.mode());
     ///     Ok(())
     /// }
     /// ```
diff --git a/src/libstd/sys/unix/ext/fs.rs b/src/libstd/sys/unix/ext/fs.rs
index d9baac993c4..c033c60cbe9 100644
--- a/src/libstd/sys/unix/ext/fs.rs
+++ b/src/libstd/sys/unix/ext/fs.rs
@@ -238,7 +238,7 @@ pub trait PermissionsExt {
     ///     let metadata = f.metadata()?;
     ///     let permissions = metadata.permissions();
     ///
-    ///     println!("permissions: {}", permissions.mode());
+    ///     println!("permissions: {:o}", permissions.mode());
     ///     Ok(()) }
     /// ```
     #[stable(feature = "fs_ext", since = "1.1.0")]