GTReflog nullability

Author: Ben Chatelain

ObjectiveGit/GTReflog+Private.h

@@ -17,6 +17,6 @@
 /// reference - The reference whose reflog is being represented. Cannot be nil.
 ///
 /// Returns the initialized object.
-- (id)initWithReference:(GTReference *)reference NS_DESIGNATED_INITIALIZER;
+- (nullable instancetype)initWithReference:(GTReference *)reference NS_DESIGNATED_INITIALIZER;
 
 @end

ObjectiveGit/GTReflog.h

@@ -11,6 +11,8 @@
 @class GTSignature;
 @class GTReflogEntry;
 
+NS_ASSUME_NONNULL_BEGIN
+
 /// A reflog for a reference. Reflogs should not be created manually. Use
 /// -[GTReference reflog] to get the reflog for a reference.
 @interface GTReflog : NSObject
@@ -32,7 +34,9 @@
 /// index - The reflog entry to get. 0 is the most recent entry. If it is greater
 ///         than `entryCount`, it will assert.
 ///
-/// Returns the entry at that index.
-- (GTReflogEntry *)entryAtIndex:(NSUInteger)index;
+/// Returns the entry at that index or nil if not found.
+- (nullable GTReflogEntry *)entryAtIndex:(NSUInteger)index;
 
 @end
+
+NS_ASSUME_NONNULL_END

ObjectiveGit/GTReflog.m

@@ -33,7 +33,7 @@ - (void)dealloc {
 	if (_git_reflog != NULL) git_reflog_free(_git_reflog);
 }
 
-- (id)initWithReference:(GTReference *)reference {
+- (instancetype)initWithReference:(GTReference *)reference {
 	NSParameterAssert(reference != nil);
 	NSParameterAssert(reference.name != nil);