2 files changed, 39 insertions, 32 deletions

diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs
index 6579b6887aa..314cbb45d49 100644
--- a/library/std/src/io/mod.rs
+++ b/library/std/src/io/mod.rs
@@ -2989,11 +2989,11 @@ impl<T: Read> Read for Take<T> {
             return Ok(());
         }
 
-        if self.limit <= buf.capacity() as u64 {
-            // if we just use an as cast to convert, limit may wrap around on a 32 bit target
-            let limit = cmp::min(self.limit, usize::MAX as u64) as usize;
+        if self.limit < buf.capacity() as u64 {
+            // The condition above guarantees that `self.limit` fits in `usize`.
+            let limit = self.limit as usize;
 
-            let extra_init = cmp::min(limit as usize, buf.init_ref().len());
+            let extra_init = cmp::min(limit, buf.init_ref().len());
 
             // SAFETY: no uninit data is written to ibuf
             let ibuf = unsafe { &mut buf.as_mut()[..limit] };
diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs
index ce46241f8e8..8fc16331339 100644
--- a/library/std/src/io/stdio.rs
+++ b/library/std/src/io/stdio.rs
@@ -97,15 +97,15 @@ const fn stderr_raw() -> StderrRaw {
 
 impl Read for StdinRaw {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        handle_ebadf(self.0.read(buf), 0)
+        handle_ebadf(self.0.read(buf), || Ok(0))
     }
 
     fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
-        handle_ebadf(self.0.read_buf(buf), ())
+        handle_ebadf(self.0.read_buf(buf), || Ok(()))
     }
 
     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        handle_ebadf(self.0.read_vectored(bufs), 0)
+        handle_ebadf(self.0.read_vectored(bufs), || Ok(0))
     }
 
     #[inline]
@@ -113,23 +113,37 @@ impl Read for StdinRaw {
         self.0.is_read_vectored()
     }
 
+    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
+        if buf.is_empty() {
+            return Ok(());
+        }
+        handle_ebadf(self.0.read_exact(buf), || Err(io::Error::READ_EXACT_EOF))
+    }
+
+    fn read_buf_exact(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
+        if buf.capacity() == 0 {
+            return Ok(());
+        }
+        handle_ebadf(self.0.read_buf_exact(buf), || Err(io::Error::READ_EXACT_EOF))
+    }
+
     fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
-        handle_ebadf(self.0.read_to_end(buf), 0)
+        handle_ebadf(self.0.read_to_end(buf), || Ok(0))
     }
 
     fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
-        handle_ebadf(self.0.read_to_string(buf), 0)
+        handle_ebadf(self.0.read_to_string(buf), || Ok(0))
     }
 }
 
 impl Write for StdoutRaw {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        handle_ebadf(self.0.write(buf), buf.len())
+        handle_ebadf(self.0.write(buf), || Ok(buf.len()))
     }
 
     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        let total = || bufs.iter().map(|b| b.len()).sum();
-        handle_ebadf_lazy(self.0.write_vectored(bufs), total)
+        let total = || Ok(bufs.iter().map(|b| b.len()).sum());
+        handle_ebadf(self.0.write_vectored(bufs), total)
     }
 
     #[inline]
@@ -138,30 +152,30 @@ impl Write for StdoutRaw {
     }
 
     fn flush(&mut self) -> io::Result<()> {
-        handle_ebadf(self.0.flush(), ())
+        handle_ebadf(self.0.flush(), || Ok(()))
     }
 
     fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
-        handle_ebadf(self.0.write_all(buf), ())
+        handle_ebadf(self.0.write_all(buf), || Ok(()))
     }
 
     fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
-        handle_ebadf(self.0.write_all_vectored(bufs), ())
+        handle_ebadf(self.0.write_all_vectored(bufs), || Ok(()))
     }
 
     fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
-        handle_ebadf(self.0.write_fmt(fmt), ())
+        handle_ebadf(self.0.write_fmt(fmt), || Ok(()))
     }
 }
 
 impl Write for StderrRaw {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        handle_ebadf(self.0.write(buf), buf.len())
+        handle_ebadf(self.0.write(buf), || Ok(buf.len()))
     }
 
     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        let total = || bufs.iter().map(|b| b.len()).sum();
-        handle_ebadf_lazy(self.0.write_vectored(bufs), total)
+        let total = || Ok(bufs.iter().map(|b| b.len()).sum());
+        handle_ebadf(self.0.write_vectored(bufs), total)
     }
 
     #[inline]
@@ -170,32 +184,25 @@ impl Write for StderrRaw {
     }
 
     fn flush(&mut self) -> io::Result<()> {
-        handle_ebadf(self.0.flush(), ())
+        handle_ebadf(self.0.flush(), || Ok(()))
     }
 
     fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
-        handle_ebadf(self.0.write_all(buf), ())
+        handle_ebadf(self.0.write_all(buf), || Ok(()))
     }
 
     fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
-        handle_ebadf(self.0.write_all_vectored(bufs), ())
+        handle_ebadf(self.0.write_all_vectored(bufs), || Ok(()))
     }
 
     fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
-        handle_ebadf(self.0.write_fmt(fmt), ())
-    }
-}
-
-fn handle_ebadf<T>(r: io::Result<T>, default: T) -> io::Result<T> {
-    match r {
-        Err(ref e) if stdio::is_ebadf(e) => Ok(default),
-        r => r,
+        handle_ebadf(self.0.write_fmt(fmt), || Ok(()))
     }
 }
 
-fn handle_ebadf_lazy<T>(r: io::Result<T>, default: impl FnOnce() -> T) -> io::Result<T> {
+fn handle_ebadf<T>(r: io::Result<T>, default: impl FnOnce() -> io::Result<T>) -> io::Result<T> {
     match r {
-        Err(ref e) if stdio::is_ebadf(e) => Ok(default()),
+        Err(ref e) if stdio::is_ebadf(e) => default(),
         r => r,
     }
 }