From 7697fbfe8a6bb8eeb18e4b95faf767ad90d90d01 Mon Sep 17 00:00:00 2001
From: Eli Bishop <eli@launchdarkly.com>
Date: Fri, 31 May 2019 10:40:55 -0700
Subject: [PATCH] prepare 5.6.5 release (#104)

---
 CHANGELOG.md                                  |  4 +++
 .../FeatureRequestor.cs                       | 15 +++++++---
 .../LaunchDarkly.ServerSdk.csproj             |  2 +-
 .../FeatureRequestorTest.cs                   | 28 +++++++++++++++++++
 4 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58a37d91..71606653 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 All notable changes to the LaunchDarkly .NET Server-Side SDK will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [5.6.5] - 2019-05-30
+### Fixed:
+- If streaming is disabled, polling requests could stop working if the client ever received an HTTP error from LaunchDarkly. This bug was introduced in the 5.6.3 release.
+
 ## [5.6.4] - 2019-05-10
 ### Changed:
 - The NuGet package name and assembly name have changed: they are now `LaunchDarkly.ServerSdk` instead of `LaunchDarkly.Client`. There are no other changes in this release; the namespace used in .NET code is still `LaunchDarkly.Client`. Substituting `LaunchDarkly.Client` version 5.6.3 with `LaunchDarkly.ServerSdk` version 5.6.4 will not affect functionality.
diff --git a/src/LaunchDarkly.ServerSdk/FeatureRequestor.cs b/src/LaunchDarkly.ServerSdk/FeatureRequestor.cs
index f7fa17cc..e0f0a513 100644
--- a/src/LaunchDarkly.ServerSdk/FeatureRequestor.cs
+++ b/src/LaunchDarkly.ServerSdk/FeatureRequestor.cs
@@ -94,15 +94,22 @@ private async Task<T> GetAsync<T>(Uri path) where T : class
                             Log.Debug("Get all flags returned 304: not modified");
                             return null;
                         }
-                        lock (_etags)
-                        {
-                            _etags[path] = response.Headers.ETag;
-                        }
                         //We ensure the status code after checking for 304, because 304 isn't considered success
                         if (!response.IsSuccessStatusCode)
                         {
                             throw new UnsuccessfulResponseException((int)response.StatusCode);
                         }
+                        lock (_etags)
+                        {
+                            if (response.Headers.ETag != null)
+                            {
+                                _etags[path] = response.Headers.ETag;
+                            }
+                            else
+                            {
+                                _etags.Remove(path);
+                            }
+                        }
                         var content = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
                         return string.IsNullOrEmpty(content) ? null : (T)JsonConvert.DeserializeObject<T>(content);
                     }
diff --git a/src/LaunchDarkly.ServerSdk/LaunchDarkly.ServerSdk.csproj b/src/LaunchDarkly.ServerSdk/LaunchDarkly.ServerSdk.csproj
index 5283e216..e6e4bab9 100644
--- a/src/LaunchDarkly.ServerSdk/LaunchDarkly.ServerSdk.csproj
+++ b/src/LaunchDarkly.ServerSdk/LaunchDarkly.ServerSdk.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <Version>5.6.4</Version>
+    <Version>5.6.5</Version>
     <TargetFrameworks>netstandard1.4;netstandard1.6;netstandard2.0;net45</TargetFrameworks>
     <PackageLicenseUrl>https://raw.githubusercontent.com/launchdarkly/dotnet-server-sdk/master/LICENSE</PackageLicenseUrl>
     <DebugType>portable</DebugType>
diff --git a/test/LaunchDarkly.ServerSdk.Tests/FeatureRequestorTest.cs b/test/LaunchDarkly.ServerSdk.Tests/FeatureRequestorTest.cs
index 316490a6..1a840ff8 100644
--- a/test/LaunchDarkly.ServerSdk.Tests/FeatureRequestorTest.cs
+++ b/test/LaunchDarkly.ServerSdk.Tests/FeatureRequestorTest.cs
@@ -173,6 +173,34 @@ public async Task ETagsDoNotConflict()
             Assert.Equal(new List<string> { etag1 }, reqs[4].RequestMessage.Headers["If-None-Match"]);
         }
 
+        [Fact]
+        public async Task ResponseWithoutEtagClearsPriorEtag()
+        {
+            var etag = @"""abc123""";
+
+            _server.Given(Request.Create().UsingGet())
+                .AtPriority(2)
+                .RespondWith(Response.Create().WithStatusCode(200).WithHeader("Etag", etag).WithBody(AllDataJson));
+            _server.Given(Request.Create().UsingGet().WithHeader("If-None-Match", etag))
+                .AtPriority(1)
+                .RespondWith(Response.Create().WithStatusCode(200).WithBody(AllDataJson)); // respond with no etag
+
+            var fetch1 = await _requestor.GetAllDataAsync();
+            var fetch2 = await _requestor.GetAllDataAsync();
+
+            _server.Given(Request.Create().UsingGet())
+                .AtPriority(1)
+                .RespondWith(Response.Create().WithStatusCode(200).WithHeader("Etag", etag).WithBody(AllDataJson));
+
+            var fetch3 = await _requestor.GetAllDataAsync();
+
+            var reqs = new List<LogEntry>(_server.LogEntries);
+            Assert.Equal(3, reqs.Count);
+            Assert.False(reqs[0].RequestMessage.Headers.ContainsKey("If-None-Match"));
+            Assert.Equal(new List<string> { etag }, reqs[1].RequestMessage.Headers["If-None-Match"]);
+            Assert.False(reqs[2].RequestMessage.Headers.ContainsKey("If-None-Match"));
+        }
+
         private RequestMessage GetLastRequest()
         {
             foreach (LogEntry le in _server.LogEntries)