Add pathspec support to GTCheckoutOptions

Author: tiennou

ObjectiveGit/GTCheckoutOptions.h

@@ -58,6 +58,9 @@ typedef NS_OPTIONS(NSInteger, GTCheckoutNotifyFlags) {
 
 @property (assign) GTCheckoutNotifyFlags notifyFlags;
 @property (copy) int (^notifyBlock)(GTCheckoutNotifyFlags why, NSString *path, GTDiffFile *baseline, GTDiffFile *target, GTDiffFile *workdir);
+
+@property (copy) NSArray *pathSpecs;
+
 @end
 
 NS_ASSUME_NONNULL_END

ObjectiveGit/GTCheckoutOptions.m

@@ -9,6 +9,7 @@
 #import "GTCheckoutOptions.h"
 #import "GTDiffFile.h"
 #import "NSError+Git.h"
+#import "NSArray+StringArray.h"
 #import "git2.h"
 
 // The type of block set in progressBlock for progress reporting
@@ -91,6 +92,8 @@ - (git_checkout_options *)git_checkoutOptions {
 		_git_checkoutOptions.notify_payload = (__bridge void *)self.notifyBlock;
 	}
 
+	_git_checkoutOptions.paths = self.pathSpecs.git_strarray;
+
 	return &_git_checkoutOptions;
 }