From 03e91573c73dbaa6afc905c6b14df4bb327589c9 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Mon, 6 Jan 2014 14:17:23 -0800
Subject: [PATCH] Don't read forever on a file descriptor

Similarly to the recent commit to do this for networking, there's no reason that
a read on a file descriptor should continue reading until the entire buffer is
full. This makes sense when dealing with literal files, but when dealing with
things like stdin this doesn't make sense.
---
 src/libnative/io/file.rs |  8 ++++----
 src/libnative/lib.rs     |  2 +-
 src/libstd/io/pipe.rs    | 22 ++++++++++++++++++++++
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/libnative/io/file.rs b/src/libnative/io/file.rs
index 0021dfcb881a..dac1ca98cf9d 100644
--- a/src/libnative/io/file.rs
+++ b/src/libnative/io/file.rs
@@ -79,10 +79,10 @@ impl FileDesc {
     pub fn inner_read(&mut self, buf: &mut [u8]) -> Result<uint, IoError> {
         #[cfg(windows)] type rlen = libc::c_uint;
         #[cfg(not(windows))] type rlen = libc::size_t;
-        let ret = keep_going(buf, |buf, len| {
-            unsafe {
-                libc::read(self.fd, buf as *mut libc::c_void, len as rlen) as i64
-            }
+        let ret = retry(|| unsafe {
+            libc::read(self.fd,
+                       buf.as_ptr() as *mut libc::c_void,
+                       buf.len() as rlen) as libc::c_int
         });
         if ret == 0 {
             Err(io::standard_error(io::EndOfFile))
diff --git a/src/libnative/lib.rs b/src/libnative/lib.rs
index 9c30e94194dd..31395216f2b5 100644
--- a/src/libnative/lib.rs
+++ b/src/libnative/lib.rs
@@ -34,7 +34,7 @@ pub mod io;
 pub mod task;
 
 // XXX: this should not exist here
-#[cfg(stage0)]
+#[cfg(stage0, nativestart)]
 #[lang = "start"]
 pub fn lang_start(main: *u8, argc: int, argv: **u8) -> int {
     use std::cast;
diff --git a/src/libstd/io/pipe.rs b/src/libstd/io/pipe.rs
index 2349c64a84b2..e3f2cc2384c2 100644
--- a/src/libstd/io/pipe.rs
+++ b/src/libstd/io/pipe.rs
@@ -80,3 +80,25 @@ impl Writer for PipeStream {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    iotest!(fn partial_read() {
+        use os;
+        use io::pipe::PipeStream;
+
+        let os::Pipe { input, out } = os::pipe();
+        let out = PipeStream::open(out);
+        let mut input = PipeStream::open(input);
+        let (p, c) = Chan::new();
+        do spawn {
+            let mut out = out;
+            out.write([10]);
+            p.recv(); // don't close the pipe until the other read has finished
+        }
+
+        let mut buf = [0, ..10];
+        input.read(buf);
+        c.send(());
+    })
+}