Confirm the behavior of NSRL

gistfile1.m

#import <Foundation/Foundation.h>

int main(void)
{
    NSURL *baseWithSlash = [NSURL URLWithString:@"http://example.com/v1/"];
    NSURL *baseWithoutSlash = [NSURL URLWithString:@"http://example.com/v1"];
    NSString *relativeWithSlash = @"/foo";
    NSString *relativeWithoutSlash = @"foo";

    // 1.baseWithSlash + relativeWithSlash
    NSURL *url = [NSURL URLWithString:relativeWithSlash relativeToURL:baseWithSlash];
    NSLog(@"%@", [url absoluteString]);

    // 2.baseWithSlash + relativeWithoutSlash
    url = [NSURL URLWithString:relativeWithoutSlash relativeToURL:baseWithSlash];
    NSLog(@"%@", [url absoluteString]);

    // 3.baseWithoutSlash + relativeWithSlash
    url = [NSURL URLWithString:relativeWithSlash relativeToURL:baseWithoutSlash];
    NSLog(@"%@", [url absoluteString]);

    // 3.baseWithoutSlash + relativeWithoutSlash
    url = [NSURL URLWithString:relativeWithoutSlash relativeToURL:baseWithoutSlash];
    NSLog(@"%@", [url absoluteString]);
}

gistfile2.txt

% clang NSURLTest.m -framework Foundation
% ./a.out
2013-02-24 22:10:39.211 a.out[28322:707] http://example.com/foo
2013-02-24 22:10:39.213 a.out[28322:707] http://example.com/v1/foo
2013-02-24 22:10:39.213 a.out[28322:707] http://example.com/foo
2013-02-24 22:10:39.214 a.out[28322:707] http://example.com/foo