From b46e3eec7aec546d8c4e212cc4e27ec870071e74 Mon Sep 17 00:00:00 2001
From: Steven Fackler <sfackler@gmail.com>
Date: Sat, 21 Feb 2015 14:59:29 -0800
Subject: [PATCH] Implement BufRead for Take

---
 src/libstd/io/mod.rs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 5e810926ee4f..d0d97c44ce55 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -681,6 +681,21 @@ impl<T: Read> Read for Take<T> {
     }
 }
 
+impl<T: BufRead> BufRead for Take<T> {
+    fn fill_buf(&mut self) -> Result<&[u8]> {
+        let buf = try!(self.inner.fill_buf());
+        let cap = cmp::min(buf.len() as u64, self.limit) as usize;
+        Ok(&buf[..cap])
+    }
+
+    fn consume(&mut self, amt: usize) {
+        // Don't let callers reset the limit by passing an overlarge value
+        let amt = cmp::min(amt as u64, self.limit) as usize;
+        self.limit -= amt as u64;
+        self.inner.consume(amt);
+    }
+}
+
 /// An adaptor which will emit all read data to a specified writer as well.
 ///
 /// For more information see `ReadExt::tee`