From 548ba15031ef7c073f236147d93dcc6125ceaa37 Mon Sep 17 00:00:00 2001
From: Arnaud Le Blanc <arnaud.lb@gmail.com>
Date: Thu, 11 Jun 2015 16:04:14 +0200
Subject: [PATCH] Fixed double-writes when write() is called during 'drain'
 event

---
 src/Buffer.php       |  4 ++--
 tests/BufferTest.php | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/Buffer.php b/src/Buffer.php
index 18211ea..e7626c6 100644
--- a/src/Buffer.php
+++ b/src/Buffer.php
@@ -111,12 +111,12 @@ public function handleWrite()
         }
 
         $len = strlen($this->data);
+        $this->data = (string) substr($this->data, $sent);
+
         if ($len >= $this->softLimit && $len - $sent < $this->softLimit) {
             $this->emit('drain', [$this]);
         }
 
-        $this->data = (string) substr($this->data, $sent);
-
         if (0 === strlen($this->data)) {
             $this->loop->removeWriteStream($this->stream);
             $this->listening = false;
diff --git a/tests/BufferTest.php b/tests/BufferTest.php
index 1fc4d1e..431c23f 100644
--- a/tests/BufferTest.php
+++ b/tests/BufferTest.php
@@ -94,6 +94,36 @@ public function testDrain()
         $buffer->write("bar\n");
     }
 
+    /**
+     * @covers React\Stream\Buffer::write
+     * @covers React\Stream\Buffer::handleWrite
+     */
+    public function testWriteInDrain()
+    {
+        $writeStreams = array();
+
+        $stream = fopen('php://temp', 'r+');
+        $loop = $this->createWriteableLoopMock();
+        $loop->preventWrites = true;
+
+        $buffer = new Buffer($stream, $loop);
+        $buffer->softLimit = 2;
+        $buffer->on('error', $this->expectCallableNever());
+
+        $buffer->once('drain', function ($buffer) {
+            $buffer->listening = false;
+            $buffer->write("bar\n");
+        });
+
+        $this->assertFalse($buffer->write("foo"));
+        $loop->preventWrites = false;
+        $buffer->listening = false;
+        $buffer->write("\n");
+
+        fseek($stream, 0);
+        $this->assertSame("foo\nbar\n", stream_get_contents($stream));
+    }
+
     /**
      * @covers React\Stream\Buffer::end
      */