From 05fc7faacb7c33eaad6614f62a7d560b0d2660a5 Mon Sep 17 00:00:00 2001
From: Elinvynia <59487684+Elinvynia@users.noreply.github.com>
Date: Sat, 9 May 2020 01:17:20 +0200
Subject: [PATCH] Better documentation for io::Read::read() return value

---
 src/libstd/io/mod.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 36c6aa620d5..ebe6d09023f 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -517,6 +517,11 @@ pub trait Read {
     ///    reader will *always* no longer be able to produce bytes.
     /// 2. The buffer specified was 0 bytes in length.
     ///
+    /// It is not an error if the returned value `n` is smaller than the buffer size,
+    /// even when the reader is not at the end of the stream yet.
+    /// This may happen for example because fewer bytes are actually available right now
+    /// (e. g. being close to end-of-file) or because read() was interrupted by a signal.
+    ///
     /// No guarantees are provided about the contents of `buf` when this
     /// function is called, implementations cannot rely on any property of the
     /// contents of `buf` being true. It is recommended that *implementations*