Optimize revision walker bindings

This simplifies the procedure used to walk revisions
by only loading in commits if the branch selection
was changed.

PBGitRepository.m

@@ -118,8 +118,8 @@ static NSString* gitPath;
 
 		if (success) {
 			[self readRefs];
-			[self readCurrentBranch];
 			revisionList = [[PBGitRevList alloc] initWithRepository:self];
+			[self readCurrentBranch];
 		}
 	}
 
@@ -133,8 +133,10 @@ static NSString* gitPath;
 	[self setFileURL: gitDirURL];
 
 	[self readRefs];
-	[self selectBranch: [self addBranch: rev]];
+
 	revisionList = [[PBGitRevList alloc] initWithRepository:self];
+	[self selectBranch: [self addBranch: rev]];
+
 	return self;
 }
 // The fileURL the document keeps is to the .git dir, but that’s pretty

PBGitRevList.m

@@ -18,8 +18,6 @@
 - initWithRepository: (id) repo
 {
 	repository = repo;
-
-	[self readCommits];
 	[repository addObserver:self forKeyPath:@"currentBranch" options:0 context:nil];
 
 	return self;
@@ -31,10 +29,13 @@
 	// we can check if the current branch is the same as the previous one
 	// and in that case we don't have to reload the revision list.
 
-	// If no branch was selected, use the current HEAD
+	// If no branch is selected, don't do anything
+	if (![repository currentBranch] || [[repository currentBranch] count] == 0)
+		return;
+
 	NSArray* selectedBranches = [[repository branches] objectsAtIndexes: [repository currentBranch]];
 
-	// Apparently, we don't have a current branch yet. Let's skip it.
+	// Apparently, The selected index does not exist.. don't do anything
 	if ([selectedBranches count] == 0)
 		return;