Added success and error information to -[GTIndex clear:]

Classes/GTIndex.h

@@ -89,7 +89,11 @@
 
 // Clear all the entries from the index. This happens in memory. Changes can be
 // written to the datastore by calling -write:.
-- (void)clear;
+//
+// error - The error if one ocurred.
+//
+// Returns whether the clear operation was successful.
+- (BOOL)clear:(NSError **)error;
 
 // Get the entry at the given index.
 //

Classes/GTIndex.m

@@ -124,8 +124,13 @@ - (BOOL)refresh:(NSError **)error {
 	return YES;
 }
 
-- (void)clear {
-	git_index_clear(self.git_index);
+- (BOOL)clear:(NSError **)error {
+	int gitError = git_index_clear(self.git_index);
+	if (gitError != GIT_OK) {
+		if (error != NULL) *error = [NSError git_errorFor:gitError description:@"Failed to clear index"];
+		return NO;
+	}
+	return YES;
 }
 
 - (GTIndexEntry *)entryAtIndex:(NSUInteger)index {

ObjectiveGitTests/GTIndexSpec.m

@@ -30,7 +30,7 @@
 });
 
 it(@"should clear all entries", ^{
-	[index clear];
+	[index clear:NULL];
 	expect(index.entryCount).to.equal(0);
 });