Use asserts because GTOID.SHA should never be nil.

Author: David Catmull

ObjectiveGit/GTOID.h

@@ -16,7 +16,7 @@ NS_ASSUME_NONNULL_BEGIN
 @interface GTOID : NSObject <NSCopying>
 
 /// The SHA pointed to by the OID.
-@property (nonatomic, readonly, copy, nullable) NSString *SHA;
+@property (nonatomic, readonly, copy) NSString *SHA;
 
 /// Is the OID all zero? This usually indicates that the object has not been
 /// inserted into the ODB yet.

ObjectiveGit/GTOID.m

@@ -28,12 +28,12 @@ - (const git_oid *)git_oid {
 
 - (NSString *)SHA {
 	char *SHA = malloc(GIT_OID_HEXSZ);
-	if (SHA == NULL) return nil;
+	NSAssert(SHA != NULL, @"Failed to malloc SHA string");
 
 	git_oid_fmt(SHA, self.git_oid);
 
 	NSString *str = [[NSString alloc] initWithBytesNoCopy:SHA length:GIT_OID_HEXSZ encoding:NSUTF8StringEncoding freeWhenDone:YES];
-	if (str == nil) free(SHA);
+	NSAssert(str != nil, @"Failed to allocate SHA string");
 	return str;
 }
 

ObjectiveGit/GTRepository.h

@@ -167,6 +167,7 @@ typedef NS_ENUM(NSInteger, GTRepositoryStateType) {
 @interface GTRepository : NSObject
 
 /// The file URL for the repository's working directory.
+/// Returns nil for a bare repository.
 @property (nonatomic, readonly, strong, nullable) NSURL *fileURL;
 /// The file URL for the repository's .git directory.
 @property (nonatomic, readonly, strong, nullable) NSURL *gitDirectoryURL;