Fix repo.Stage("*") behavior

 - Drop unnecessary detection of renames and copies
 - Always perform removals from the Index before additions

Author: nulltoken

LibGit2Sharp.Tests/IndexFixture.cs

@@ -443,5 +443,39 @@ public void AddingAnEntryToTheIndexFromAUnknwonFileInTheWorkdirThrows()
                 Assert.Throws<NotFoundException>(() => repo.Index.Add(filePath));
             }
         }
+
+        [Fact]
+        public void CanMimicGitAddAll()
+        {
+            var path = SandboxStandardTestRepoGitDir();
+            using (var repo = new Repository(path))
+            {
+                var before = repo.RetrieveStatus();
+                Assert.True(before.Any(se => se.State == FileStatus.Untracked));
+                Assert.True(before.Any(se => se.State == FileStatus.Modified));
+                Assert.True(before.Any(se => se.State == FileStatus.Missing));
+
+                AddSomeCornerCases(repo);
+
+                repo.Stage("*");
+
+                var after = repo.RetrieveStatus();
+                Assert.False(after.Any(se => se.State == FileStatus.Untracked));
+                Assert.False(after.Any(se => se.State == FileStatus.Modified));
+                Assert.False(after.Any(se => se.State == FileStatus.Missing));
+            }
+        }
+
+        private static void AddSomeCornerCases(Repository repo)
+        {
+            // Turn 1.txt into a directory in the Index
+            repo.Index.Remove("1.txt");
+            var blob = repo.Lookup<Blob>("a8233120f6ad708f843d861ce2b7228ec4e3dec6");
+            repo.Index.Add(blob, "1.txt/Sneaky", Mode.NonExecutableFile);
+
+            // Turn README into a symlink
+            Blob linkContent = OdbHelper.CreateBlob(repo, "1.txt/sneaky");
+            repo.Index.Add(linkContent, "README", Mode.SymbolicLink);
+        }
     }
 }

LibGit2Sharp/Repository.cs

@@ -1493,28 +1493,41 @@ public void Stage(IEnumerable<string> paths, StageOptions stageOptions)
                 diffModifiers |= DiffModifiers.IncludeIgnored;
             }
 
-            var changes = Diff.Compare<TreeChanges>(diffModifiers, paths, explicitPathsOptions);
+            var changes = Diff.Compare<TreeChanges>(diffModifiers, paths, explicitPathsOptions,
+                new CompareOptions { Similarity = SimilarityOptions.None });
 
-            foreach (var treeEntryChanges in changes)
+            var unexpectedTypesOfChanges = changes
+                .Where(
+                    tec => tec.Status != ChangeKind.Added &&
+                           tec.Status != ChangeKind.Modified &&
+                           tec.Status != ChangeKind.Unmodified &&
+                           tec.Status != ChangeKind.Deleted).ToList();
+
+            if (unexpectedTypesOfChanges.Count > 0)
             {
-                switch (treeEntryChanges.Status)
-                {
-                    case ChangeKind.Unmodified:
-                        continue;
+                throw new InvalidOperationException(
+                    string.Format(CultureInfo.InvariantCulture,
+                        "Entry '{0}' bears an unexpected ChangeKind '{1}'",
+                        unexpectedTypesOfChanges[0].Path, unexpectedTypesOfChanges[0].Status));
+            }
 
-                    case ChangeKind.Deleted:
-                        RemoveFromIndex(treeEntryChanges.Path);
-                        continue;
+            foreach (TreeEntryChanges treeEntryChanges in changes
+                .Where(tec => tec.Status == ChangeKind.Deleted))
+            {
+                RemoveFromIndex(treeEntryChanges.Path);
+            }
 
+            foreach (TreeEntryChanges treeEntryChanges in changes)
+            {
+                switch (treeEntryChanges.Status)
+                {
                     case ChangeKind.Added:
-                    /* Fall through */
                     case ChangeKind.Modified:
                         AddToIndex(treeEntryChanges.Path);
-                        continue;
+                        break;
 
                     default:
-                        throw new InvalidOperationException(
-                            string.Format(CultureInfo.InvariantCulture, "Entry '{0}' bears an unexpected ChangeKind '{1}'", treeEntryChanges.Path, treeEntryChanges.Status));
+                        continue;
                 }
             }