Fix Checkout behavior when dealing with Head

Saaman · Saaman · commit 0efaf0d25814 · 2013-04-26T14:05:57.000+02:00
diff --git a/LibGit2Sharp.Tests/CheckoutFixture.cs b/LibGit2Sharp.Tests/CheckoutFixture.cs
@@ -610,6 +610,40 @@ public void CheckoutLowerCasedHeadThrows()
             }
         }
 
+        [Fact]
+        public void CanCheckoutAttachedHead()
+        {
+            string path = CloneStandardTestRepo();
+            using (var repo = new Repository(path))
+            {
+                Assert.False(repo.Info.IsHeadDetached);
+
+                repo.Checkout(repo.Head);
+                Assert.False(repo.Info.IsHeadDetached);
+
+                repo.Checkout("HEAD");
+                Assert.False(repo.Info.IsHeadDetached);
+            }
+        }
+
+        [Fact]
+        public void CanCheckoutDetachedHead()
+        {
+            string path = CloneStandardTestRepo();
+            using (var repo = new Repository(path))
+            {
+                repo.Checkout(repo.Head.Tip.Sha);
+
+                Assert.True(repo.Info.IsHeadDetached);
+
+                repo.Checkout(repo.Head);
+                Assert.True(repo.Info.IsHeadDetached);
+
+                repo.Checkout("HEAD");
+                Assert.True(repo.Info.IsHeadDetached);
+            }
+        }
+
         /// <summary>
         ///   Helper method to populate a simple repository with
         ///   a single file and two branches.
diff --git a/LibGit2Sharp/Repository.cs b/LibGit2Sharp/Repository.cs
@@ -597,6 +597,11 @@ public Branch Checkout(string committishOrBranchSpec, CheckoutOptions checkoutOp
 
         private Branch TryResolveBranch(string committishOrBranchSpec)
         {
+            if (committishOrBranchSpec == "HEAD")
+            {
+                return Head;
+            }
+
             try
             {
                 return Branches[committishOrBranchSpec];
@@ -631,7 +636,7 @@ public Branch Checkout(Branch branch, CheckoutOptions checkoutOptions, CheckoutP
             CheckoutTree(branch.Tip.Tree, checkoutOptions, onCheckoutProgress);
 
             // Update HEAD.
-            if (!branch.IsRemote &&
+            if (!branch.IsRemote && !(branch is DetachedHead) &&
                 string.Equals(Refs[branch.CanonicalName].TargetIdentifier, branch.Tip.Id.Sha,
                 StringComparison.OrdinalIgnoreCase))
             {

Original file line number	Diff line number	Diff line change
`@@ -597,6 +597,11 @@ public Branch Checkout(string committishOrBranchSpec, CheckoutOptions checkoutOp`
`597`	`597`
`598`	`598`	`private Branch TryResolveBranch(string committishOrBranchSpec)`
`599`	`599`	`{`
	`600`	`+ if (committishOrBranchSpec == "HEAD")`
	`601`	`+ {`
	`602`	`+ return Head;`
	`603`	`+ }`
	`604`	`+`
`600`	`605`	`try`
`601`	`606`	`{`
`602`	`607`	`return Branches[committishOrBranchSpec];`
`@@ -631,7 +636,7 @@ public Branch Checkout(Branch branch, CheckoutOptions checkoutOptions, CheckoutP`
`631`	`636`	`CheckoutTree(branch.Tip.Tree, checkoutOptions, onCheckoutProgress);`
`632`	`637`
`633`	`638`	`// Update HEAD.`
`634`		`- if (!branch.IsRemote &&`
	`639`	`+ if (!branch.IsRemote && !(branch is DetachedHead) &&`
`635`	`640`	`string.Equals(Refs[branch.CanonicalName].TargetIdentifier, branch.Tip.Id.Sha,`
`636`	`641`	`StringComparison.OrdinalIgnoreCase))`
`637`	`642`	`{`