Make Diff.Compare() able to compare null Blobs

nulltoken · nulltoken · commit ec1a6b7af9fe · 2012-11-29T20:08:17.000+01:00
diff --git a/LibGit2Sharp.Tests/DiffBlobToBlobFixture.cs b/LibGit2Sharp.Tests/DiffBlobToBlobFixture.cs
@@ -89,5 +89,40 @@ public void CanCompareATextualBlobAgainstABinaryBlob()
                 Assert.Equal(0, changes.LinesDeleted);
             }
         }
+
+        [Fact]
+        public void CanCompareABlobAgainstANullBlob()
+        {
+            using (var repo = new Repository(StandardTestRepoPath))
+            {
+                Blob blob = repo.Head.Tip.Tree.Blobs.First();
+
+                ContentChanges changes = repo.Diff.Compare(null, blob);
+
+                Assert.NotEqual(0, changes.LinesAdded);
+                Assert.Equal(0, changes.LinesDeleted);
+                Assert.NotEqual(string.Empty, changes.Patch);
+
+                changes = repo.Diff.Compare(blob, null);
+
+                Assert.Equal(0, changes.LinesAdded);
+                Assert.NotEqual(0, changes.LinesDeleted);
+                Assert.NotEqual(string.Empty, changes.Patch);
+            }
+        }
+
+        [Fact]
+        public void ComparingTwoNullBlobsReturnsAnEmptyContentChanges()
+        {
+            using (var repo = new Repository(StandardTestRepoPath))
+            {
+                ContentChanges changes = repo.Diff.Compare((Blob)null, (Blob)null);
+
+                Assert.False(changes.IsBinaryComparison);
+
+                Assert.Equal(0, changes.LinesAdded);
+                Assert.Equal(0, changes.LinesDeleted);
+            }
+        }
     }
 }
diff --git a/LibGit2Sharp/ContentChanges.cs b/LibGit2Sharp/ContentChanges.cs
@@ -17,7 +17,10 @@ protected ContentChanges()
 
         internal ContentChanges(Repository repo, Blob oldBlob, Blob newBlob, GitDiffOptions options)
         {
-            Proxy.git_diff_blobs(repo.Handle, oldBlob, newBlob, options, FileCallback, HunkCallback, LineCallback);
+            Proxy.git_diff_blobs(repo.Handle,
+                                 oldBlob != null ? oldBlob.Id : null,
+                                 newBlob != null ? newBlob.Id : null,
+                                 options, FileCallback, HunkCallback, LineCallback);
         }
 
         private int FileCallback(IntPtr data, GitDiffDelta delta, float progress)
diff --git a/LibGit2Sharp/Core/Proxy.cs b/LibGit2Sharp/Core/Proxy.cs
@@ -488,16 +488,16 @@ public static ICollection<TResult> git_config_foreach<TResult>(
 
         public static void git_diff_blobs(
             RepositorySafeHandle repo,
-            Blob oldBlob,
-            Blob newBlob,
+            ObjectId oldBlob,
+            ObjectId newBlob,
             GitDiffOptions options,
             NativeMethods.git_diff_file_fn fileCallback,
             NativeMethods.git_diff_hunk_fn hunkCallback,
             NativeMethods.git_diff_data_fn lineCallback)
         {
             using (ThreadAffinity())
-            using (var osw1 = new ObjectSafeWrapper(oldBlob.Id, repo))
-            using (var osw2 = new ObjectSafeWrapper(newBlob.Id, repo))
+            using (var osw1 = new ObjectSafeWrapper(oldBlob, repo, true))
+            using (var osw2 = new ObjectSafeWrapper(newBlob, repo, true))
             {
                 int res = NativeMethods.git_diff_blobs(osw1.ObjectPtr, osw2.ObjectPtr, options, IntPtr.Zero, fileCallback, hunkCallback, lineCallback);
                 Ensure.Success(res);

Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,10 @@ protected ContentChanges()`
`17`	`17`
`18`	`18`	`internal ContentChanges(Repository repo, Blob oldBlob, Blob newBlob, GitDiffOptions options)`
`19`	`19`	`{`
`20`		`- Proxy.git_diff_blobs(repo.Handle, oldBlob, newBlob, options, FileCallback, HunkCallback, LineCallback);`
	`20`	`+ Proxy.git_diff_blobs(repo.Handle,`
	`21`	`+ oldBlob != null ? oldBlob.Id : null,`
	`22`	`+ newBlob != null ? newBlob.Id : null,`
	`23`	`+ options, FileCallback, HunkCallback, LineCallback);`
`21`	`24`	`}`
`22`	`25`
`23`	`26`	`private int FileCallback(IntPtr data, GitDiffDelta delta, float progress)`