fix(http): keep flushing until WOULDBLOCK is received

src/http/io.rs

@@ -129,14 +129,13 @@ impl<T: Write> Write for Buffered<T> {
         if self.write_buf.remaining() == 0 {
             Ok(())
         } else {
-            self.write_buf.write_into(&mut self.io).and_then(|n| {
+            loop {
+                let n = try!(self.write_buf.write_into(&mut self.io));
                 debug!("flushed {} bytes", n);
                 if self.write_buf.remaining() == 0 {
-                    Ok(())
-                } else {
-                    Err(io::Error::new(io::ErrorKind::WouldBlock, "wouldblock"))
+                    return Ok(())
                 }
-            })
+            }
         }
     }
 }
@@ -295,7 +294,6 @@ impl WriteBuf {
             trace!("WriteBuf reserving initial {}", init);
             vec.reserve(init);
         } else if cap < MAX_BUFFER_SIZE {
-            trace!("maybe_reserve MAX={}, needed={}, cap={}", MAX_BUFFER_SIZE, needed, cap);
             vec.reserve(cmp::min(needed, MAX_BUFFER_SIZE - cap));
             trace!("WriteBuf reserved {}", vec.capacity() - cap);
         }