1 files changed, 23 insertions, 1 deletions
diff --git a/library/std/src/sys/windows/pipe.rs b/library/std/src/sys/windows/pipe.rs
index 7b25edaa5..0780b2958 100644
--- a/library/std/src/sys/windows/pipe.rs
+++ b/library/std/src/sys/windows/pipe.rs
@@ -1,7 +1,7 @@
 use crate::os::windows::prelude::*;
 
 use crate::ffi::OsStr;
-use crate::io::{self, IoSlice, IoSliceMut, Read};
+use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read};
 use crate::mem;
 use crate::path::Path;
 use crate::ptr;
@@ -252,6 +252,28 @@ impl AnonPipe {
         }
     }
 
+    pub fn read_buf(&self, mut buf: BorrowedCursor<'_>) -> io::Result<()> {
+        let result = unsafe {
+            let len = crate::cmp::min(buf.capacity(), c::DWORD::MAX as usize) as c::DWORD;
+            self.alertable_io_internal(c::ReadFileEx, buf.as_mut().as_mut_ptr() as _, len)
+        };
+
+        match result {
+            // The special treatment of BrokenPipe is to deal with Windows
+            // pipe semantics, which yields this error when *reading* from
+            // a pipe after the other end has closed; we interpret that as
+            // EOF on the pipe.
+            Err(ref e) if e.kind() == io::ErrorKind::BrokenPipe => Ok(()),
+            Err(e) => Err(e),
+            Ok(n) => {
+                unsafe {
+                    buf.advance(n);
+                }
+                Ok(())
+            }
+        }
+    }
+
     pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         self.inner.read_vectored(bufs)
     }