From 1f28e381f2f1282efa040ad574b0ddd8c4b1708e Mon Sep 17 00:00:00 2001
From: Stanley Goldman <Stanley.Goldman@gmail.com>
Date: Mon, 31 Jul 2017 17:28:28 -0400
Subject: [PATCH 1/2] Checking for empty paths as well as null

---
 src/GitHub.Api/IO/FileSystemHelpers.cs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/GitHub.Api/IO/FileSystemHelpers.cs b/src/GitHub.Api/IO/FileSystemHelpers.cs
index afa7cb417..fe16cdb6c 100644
--- a/src/GitHub.Api/IO/FileSystemHelpers.cs
+++ b/src/GitHub.Api/IO/FileSystemHelpers.cs
@@ -7,12 +7,16 @@ static class FileSystemHelpers
     {
         public static string FindCommonPath(IEnumerable<string> paths)
         {
-            var pathsArray = paths.Where(s => s != null).Select(s => s.ToNPath().Parent).ToArray();
-            var maxDepth = pathsArray.Max(path => path.Depth);
-            var deepestPath = pathsArray.First(path => path.Depth == maxDepth);
+            var parentPaths = paths.Where(s => !string.IsNullOrEmpty(s)).Select(s => s.ToNPath().Parent);
+            if (!parentPaths.Any())
+                return null;
+
+            var parentsArray = parentPaths.ToArray();
+            var maxDepth = parentsArray.Max(path => path.Depth);
+            var deepestPath = parentsArray.First(path => path.Depth == maxDepth);
 
             var commonParent = deepestPath;
-            foreach (var path in pathsArray)
+            foreach (var path in parentsArray)
             {
                 var cp = path.Elements.Any() ? commonParent.GetCommonParent(path) : null;
                 if (cp != null)

From e424f46e3caf99434f73aa56c2c35432b49a9349 Mon Sep 17 00:00:00 2001
From: Stanley Goldman <Stanley.Goldman@gmail.com>
Date: Mon, 31 Jul 2017 18:29:26 -0400
Subject: [PATCH 2/2] Empty paths test fix

---
 src/tests/UnitTests/IO/FileSystemHelperTests.cs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/tests/UnitTests/IO/FileSystemHelperTests.cs b/src/tests/UnitTests/IO/FileSystemHelperTests.cs
index 9b4f8d22d..46408ea3b 100644
--- a/src/tests/UnitTests/IO/FileSystemHelperTests.cs
+++ b/src/tests/UnitTests/IO/FileSystemHelperTests.cs
@@ -27,18 +27,18 @@ public void TestFixtureTearDown()
         }
 
         [Test]
-        public void ShouldErrorIfEmpty()
+        public void ShouldNotErrorIfEmpty()
         {
             Action item;
 
             item = () => { FileSystemHelpers.FindCommonPath(new List<string>()); };
-            item.ShouldThrow<InvalidOperationException>();
+            item.ShouldNotThrow<InvalidOperationException>();
 
             item = () => { FileSystemHelpers.FindCommonPath(new List<string> { null }); };
-            item.ShouldThrow<InvalidOperationException>();
+            item.ShouldNotThrow<InvalidOperationException>();
 
             item = () => { FileSystemHelpers.FindCommonPath(new List<string> { "" }); };
-            item.ShouldThrow<InvalidOperationException>();
+            item.ShouldNotThrow<InvalidOperationException>();
         }
 
         [Test]