fix issue 2439

- checks buildagent to set NoFetch argument when invoked without any
  command line arguments

Author: David Korfkamp

src/GitVersionExe.Tests/ArgumentParserOnBuildServerTests.cs

@@ -0,0 +1,63 @@
+using System;
+using GitVersion;
+using GitVersion.OutputVariables;
+using GitVersionCore.Tests.Helpers;
+using Microsoft.Extensions.DependencyInjection;
+using NUnit.Framework;
+using Shouldly;
+
+namespace GitVersionExe.Tests
+{
+    [TestFixture]
+    public class ArgumentParserOnBuildServerTests : TestBase
+    {
+        private IArgumentParser argumentParser;
+
+        [SetUp]
+        public void SetUp()
+        {
+            var sp = ConfigureServices(services =>
+            {
+                services.AddSingleton<IArgumentParser, ArgumentParser>();
+                services.AddSingleton<IGlobbingResolver, GlobbingResolver>();
+                services.AddSingleton<ICurrentBuildAgent, MockBuildAgent>();
+            });
+            argumentParser = sp.GetService<IArgumentParser>();
+        }
+
+        [Test]
+        public void EmptyOnFetchDisabledBuildServerMeansNoFetchIsTrue()
+        {
+            var arguments = argumentParser.ParseArguments("");
+            arguments.NoFetch.ShouldBe(true);
+        }
+
+        private class MockBuildAgent : ICurrentBuildAgent
+        {
+            public bool CanApplyToCurrentContext()
+            {
+                throw new NotImplementedException();
+            }
+
+            public void WriteIntegration(Action<string> writer, VersionVariables variables, bool updateBuildNumber = true)
+            {
+                throw new NotImplementedException();
+            }
+
+            public string GetCurrentBranch(bool usingDynamicRepos)
+            {
+                throw new NotImplementedException();
+            }
+
+            public bool PreventFetch()
+            {
+                return true;
+            }
+
+            public bool ShouldCleanUpRemotes()
+            {
+                throw new NotImplementedException();
+            }
+        }
+    }
+}

src/GitVersionExe/ArgumentParser.cs

@@ -49,6 +49,8 @@ public Arguments ParseArguments(string[] commandLineArguments)
 
                 AddAuthentication(args);
 
+                args.NoFetch = buildAgent != null && buildAgent.PreventFetch();
+
                 return args;
             }