From 301a70c4995b07fd29b8b32edad72dc77797e8c1 Mon Sep 17 00:00:00 2001
From: joshaber <joshaber@gmail.com>
Date: Fri, 12 Dec 2014 12:44:29 -0500
Subject: [PATCH 1/4] Stub out a test.

---
 ObjectiveGitTests/GTBranchSpec.m | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ObjectiveGitTests/GTBranchSpec.m b/ObjectiveGitTests/GTBranchSpec.m
index 631207b05..b11eb79be 100644
--- a/ObjectiveGitTests/GTBranchSpec.m
+++ b/ObjectiveGitTests/GTBranchSpec.m
@@ -189,6 +189,10 @@
 	});
 });
 
+describe(@"-updateTrackingBranch:error:", ^{
+
+});
+
 // TODO: Test branch renaming, branch upstream
 //- (void)testCanRenameBranch {
 //

From 7c64ab71171ad22b3e774fd653f146ca91e92c55 Mon Sep 17 00:00:00 2001
From: joshaber <joshaber@gmail.com>
Date: Fri, 12 Dec 2014 11:56:32 -0500
Subject: [PATCH 2/4] Added -updateTrackingBranch:error:.

---
 ObjectiveGit/GTBranch.h |  9 +++++++++
 ObjectiveGit/GTBranch.m | 10 ++++++++++
 2 files changed, 19 insertions(+)

diff --git a/ObjectiveGit/GTBranch.h b/ObjectiveGit/GTBranch.h
index d2d7a56c8..43734ffb4 100644
--- a/ObjectiveGit/GTBranch.h
+++ b/ObjectiveGit/GTBranch.h
@@ -79,6 +79,15 @@ typedef NS_ENUM(NSInteger, GTBranchType) {
 /// found, returns nil and sets `success` to YES.
 - (GTBranch *)trackingBranchWithError:(NSError **)error success:(BOOL *)success;
 
+/// Update the tracking branch.
+///
+/// trackingBranch - The tracking branch for the receiver. If nil, it unsets the
+///                  tracking branch.
+/// error          - The error if one occurred.
+///
+/// Returns whether it was successful.
+- (BOOL)updateTrackingBranch:(GTBranch *)trackingBranch error:(NSError **)error;
+
 /// Reloads the branch's reference and creates a new branch based off that newly
 /// loaded reference.
 ///
diff --git a/ObjectiveGit/GTBranch.m b/ObjectiveGit/GTBranch.m
index 8516a424f..0fc734483 100644
--- a/ObjectiveGit/GTBranch.m
+++ b/ObjectiveGit/GTBranch.m
@@ -205,6 +205,16 @@ - (GTBranch *)trackingBranchWithError:(NSError **)error success:(BOOL *)success
 	return [[self class] branchWithReference:[[GTReference alloc] initWithGitReference:trackingRef repository:self.repository] repository:self.repository];
 }
 
+- (BOOL)updateTrackingBranch:(GTBranch *)trackingBranch error:(NSError **)error {
+	int result = git_branch_set_upstream(self.reference.git_reference, trackingBranch.name.UTF8String);
+	if (result != GIT_OK) {
+		if (error != NULL) *error = [NSError git_errorFor:result description:@"Failed to update tracking branch for %@", self];
+		return NO;
+	}
+
+	return YES;
+}
+
 - (GTBranch *)reloadedBranchWithError:(NSError **)error {
 	GTReference *reloadedRef = [self.reference reloadedReferenceWithError:error];
 	if (reloadedRef == nil) return nil;

From 526936318f039f85e134ea4e9ff7819d7094be41 Mon Sep 17 00:00:00 2001
From: joshaber <joshaber@gmail.com>
Date: Fri, 12 Dec 2014 13:54:14 -0500
Subject: [PATCH 3/4] Use the short name.

---
 ObjectiveGit/GTBranch.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ObjectiveGit/GTBranch.m b/ObjectiveGit/GTBranch.m
index 0fc734483..f5762bb01 100644
--- a/ObjectiveGit/GTBranch.m
+++ b/ObjectiveGit/GTBranch.m
@@ -206,7 +206,7 @@ - (GTBranch *)trackingBranchWithError:(NSError **)error success:(BOOL *)success
 }
 
 - (BOOL)updateTrackingBranch:(GTBranch *)trackingBranch error:(NSError **)error {
-	int result = git_branch_set_upstream(self.reference.git_reference, trackingBranch.name.UTF8String);
+	int result = git_branch_set_upstream(self.reference.git_reference, trackingBranch.shortName.UTF8String);
 	if (result != GIT_OK) {
 		if (error != NULL) *error = [NSError git_errorFor:result description:@"Failed to update tracking branch for %@", self];
 		return NO;

From 6085301725d4fa6974817a736a60a23d0b2850c4 Mon Sep 17 00:00:00 2001
From: joshaber <joshaber@gmail.com>
Date: Fri, 12 Dec 2014 13:54:21 -0500
Subject: [PATCH 4/4] Test it.

---
 ObjectiveGitTests/GTBranchSpec.m | 37 ++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/ObjectiveGitTests/GTBranchSpec.m b/ObjectiveGitTests/GTBranchSpec.m
index b11eb79be..f3537ea1e 100644
--- a/ObjectiveGitTests/GTBranchSpec.m
+++ b/ObjectiveGitTests/GTBranchSpec.m
@@ -190,7 +190,44 @@
 });
 
 describe(@"-updateTrackingBranch:error:", ^{
+	__block GTBranch *masterBranch;
+	beforeEach(^{
+		masterBranch = [repository lookUpBranchWithName:@"master" type:GTBranchTypeLocal success:NULL error:NULL];
+		expect(masterBranch).notTo(beNil());
+	});
+
+	it(@"should set a tracking branch", ^{
+		GTBranch *branch = [repository lookUpBranchWithName:@"feature" type:GTBranchTypeLocal success:NULL error:NULL];
+		expect(branch).notTo(beNil());
+
+		BOOL success = NO;
+		GTBranch *trackingBranch = [branch trackingBranchWithError:NULL success:&success];
+		expect(trackingBranch).to(beNil());
+		expect(@(success)).to(beTruthy());
+
+		NSError *error;
+		success = [branch updateTrackingBranch:masterBranch error:&error];
+		expect(@(success)).to(beTruthy());
+		expect(error).to(beNil());
 
+		trackingBranch = [branch trackingBranchWithError:NULL success:&success];
+		expect(trackingBranch).notTo(beNil());
+		expect(@(success)).to(beTruthy());
+	});
+
+	it(@"should unset a tracking branch", ^{
+		BOOL success = NO;
+		GTBranch *trackingBranch = [masterBranch trackingBranchWithError:NULL success:&success];
+		expect(trackingBranch).notTo(beNil());
+		expect(@(success)).to(beTruthy());
+
+		success = [masterBranch updateTrackingBranch:nil error:NULL];
+		expect(@(success)).to(beTruthy());
+
+		trackingBranch = [masterBranch trackingBranchWithError:NULL success:&success];
+		expect(trackingBranch).to(beNil());
+		expect(@(success)).to(beTruthy());
+	});
 });
 
 // TODO: Test branch renaming, branch upstream