From 94c3bb631cce3a46178c19c6f42844255a982714 Mon Sep 17 00:00:00 2001
From: Aaron Piotrowski <aaron@trowski.com>
Date: Mon, 7 Jan 2019 11:32:42 -0600
Subject: [PATCH] Avoid warning when writing an empty string with eio

No warning emitted from uv, but there's also no reason to call uv_fs_write().
---
 lib/EioHandle.php   |  4 ++++
 lib/UvHandle.php    |  4 ++++
 test/HandleTest.php | 15 +++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/lib/EioHandle.php b/lib/EioHandle.php
index a4e848a..14adb2f 100644
--- a/lib/EioHandle.php
+++ b/lib/EioHandle.php
@@ -132,6 +132,10 @@ class EioHandle implements Handle
     {
         $length = \strlen($data);
 
+        if ($length === 0) {
+            return new Success(0);
+        }
+
         $deferred = new Deferred;
         $this->poll->listen($deferred->promise());
 
diff --git a/lib/UvHandle.php b/lib/UvHandle.php
index b12b23e..d693a76 100644
--- a/lib/UvHandle.php
+++ b/lib/UvHandle.php
@@ -150,6 +150,10 @@ class UvHandle implements Handle
     {
         $length = \strlen($data);
 
+        if ($length === 0) {
+            return new Success(0);
+        }
+
         $deferred = new Deferred;
         $this->poll->listen($deferred->promise());
 
diff --git a/test/HandleTest.php b/test/HandleTest.php
index 6f2f4e7..8b5dd14 100644
--- a/test/HandleTest.php
+++ b/test/HandleTest.php
@@ -41,6 +41,21 @@ abstract class HandleTest extends TestCase
         });
     }
 
+    public function testEmptyWrite()
+    {
+        $this->execute(function () {
+            $path = Fixture::path() . "/write";
+
+            $handle = yield File\open($path, "c+");
+            $this->assertSame(0, $handle->tell());
+
+            yield $handle->write("");
+            $this->assertSame(0, $handle->tell());
+
+            yield $handle->close();
+        });
+    }
+
     public function testWriteAfterClose()
     {
         $this->execute(function () {