GitProcess: allow GIT_TRACE to point to full path

GVFS/GVFS.Common/Git/GitProcess.cs

@@ -1,6 +1,5 @@
 using GVFS.Common.FileSystem;
 using GVFS.Common.Tracing;
-using Microsoft.Win32;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
@@ -149,7 +148,7 @@ public bool IsValidRepo()
             Result result = this.InvokeGitAgainstDotGitFolder("rev-parse --show-toplevel");
             return !result.HasErrors;
         }
-                
+
         public Result RevParse(string gitRef)
         {
             return this.InvokeGitAgainstDotGitFolder("rev-parse " + gitRef);
@@ -405,11 +404,24 @@ public Process GetGitProcess(string command, string workingDirectory, string dot
 
             // Removing trace variables that might change git output and break parsing
             // List of environment variables: https://git-scm.com/book/gr/v2/Git-Internals-Environment-Variables
-            foreach (string key in processInfo.EnvironmentVariables.Keys.Cast<string>()
-                .Where(x => x.StartsWith("GIT_TRACE", StringComparison.OrdinalIgnoreCase))
-                .ToList())
+            foreach (string key in processInfo.EnvironmentVariables.Keys.Cast<string>().ToList())
             {
-                processInfo.EnvironmentVariables.Remove(key);
+                // If GIT_TRACE is set to a fully-rooted path, then Git sends the trace
+                // output to that path instead of stdout (GIT_TRACE=1) or stderr (GIT_TRACE=2).
+                if (key.StartsWith("GIT_TRACE", StringComparison.OrdinalIgnoreCase))
+                {
+                    try
+                    {
+                        if (!Path.IsPathRooted(processInfo.EnvironmentVariables[key]))
+                        {
+                            processInfo.EnvironmentVariables.Remove(key);
+                        }
+                    }
+                    catch (ArgumentException)
+                    {
+                        processInfo.EnvironmentVariables.Remove(key);
+                    }
+                }
             }
 
             processInfo.EnvironmentVariables["GIT_TERMINAL_PROMPT"] = "0";
@@ -601,7 +613,7 @@ private Result InvokeGitAgainstDotGitFolder(
                 parseStdOutLine: parseStdOutLine,
                 timeoutMs: -1);
         }
-        
+
         public class Result
         {
             public const int SuccessCode = 0;

GVFS/GVFS.FunctionalTests/Tests/EnlistmentPerFixture/StatusVerbTests.cs

@@ -0,0 +1,34 @@
+using GVFS.FunctionalTests.FileSystemRunners;
+using GVFS.Tests.Should;
+using NUnit.Framework;
+using System.Collections.Generic;
+using System.IO;
+
+namespace GVFS.FunctionalTests.Tests.EnlistmentPerFixture
+{
+    [TestFixture]
+    public class StatusVerbTests : TestsWithEnlistmentPerFixture
+    {
+        private enum ExpectedReturnCode
+        {
+            Success = 0,
+            ParsingError = 1,
+        }
+
+        [TestCase]
+        public void GitTrace()
+        {
+            Dictionary<string, string> environmentVariables = new Dictionary<string, string>();
+
+            this.Enlistment.Status(trace: "1");
+            this.Enlistment.Status(trace: "2");
+
+            string logPath = Path.Combine(this.Enlistment.RepoRoot, "log-file.txt");
+            this.Enlistment.Status(trace: logPath);
+
+            FileSystemRunner fileSystem = new SystemIORunner();
+            fileSystem.FileExists(logPath).ShouldBeTrue();
+            string.IsNullOrWhiteSpace(fileSystem.ReadAllText(logPath)).ShouldBeFalse();
+        }
+    }
+}

GVFS/GVFS.FunctionalTests/Tools/GVFSFunctionalTestEnlistment.cs

@@ -207,9 +207,9 @@ public string Diagnose()
             return this.gvfsProcess.Diagnose();
         }
 
-        public string Status()
+        public string Status(string trace = null)
         {
-            return this.gvfsProcess.Status();
+            return this.gvfsProcess.Status(trace);
         }
 
         public bool WaitForBackgroundOperations(int maxWaitMilliseconds = DefaultMaxWaitMSForStatusCheck)

GVFS/GVFS.FunctionalTests/Tools/GVFSProcess.cs

@@ -8,14 +8,14 @@ public class GVFSProcess
         private readonly string pathToGVFS;
         private readonly string enlistmentRoot;
         private readonly string localCacheRoot;
-        
+
         public GVFSProcess(string pathToGVFS, string enlistmentRoot, string localCacheRoot)
         {
             this.pathToGVFS = pathToGVFS;
             this.enlistmentRoot = enlistmentRoot;
             this.localCacheRoot = localCacheRoot;
         }
-        
+
         public void Clone(string repositorySource, string branchToCheckout, bool skipPrefetch)
         {
             string args = string.Format(
@@ -50,7 +50,7 @@ public string Prefetch(string args, bool failOnError)
         public void Repair()
         {
             this.CallGVFS(
-                "repair --confirm \"" + this.enlistmentRoot + "\"", 
+                "repair --confirm \"" + this.enlistmentRoot + "\"",
                 failOnError: true);
         }
 
@@ -59,9 +59,9 @@ public string Diagnose()
             return this.CallGVFS("diagnose \"" + this.enlistmentRoot + "\"");
         }
 
-        public string Status()
+        public string Status(string trace = null)
         {
-            return this.CallGVFS("status " + this.enlistmentRoot);
+            return this.CallGVFS("status " + this.enlistmentRoot, trace: trace);
         }
 
         public string CacheServer(string args)
@@ -89,7 +89,7 @@ public string RunServiceVerb(string argument)
             return this.CallGVFS("service " + argument, failOnError: true);
         }
 
-        private string CallGVFS(string args, bool failOnError = false)
+        private string CallGVFS(string args, bool failOnError = false, string trace = null)
         {
             ProcessStartInfo processInfo = null;
             processInfo = new ProcessStartInfo(this.pathToGVFS);
@@ -99,6 +99,11 @@ private string CallGVFS(string args, bool failOnError = false)
             processInfo.UseShellExecute = false;
             processInfo.RedirectStandardOutput = true;
 
+            if (trace != null)
+            {
+                processInfo.EnvironmentVariables["GIT_TRACE"] = trace;
+            }
+
             using (Process process = Process.Start(processInfo))
             {
                 string result = process.StandardOutput.ReadToEnd();