Open Radar

 
Summary:
I have noticed that when entering asian letters and emoji in my iOS app that my app is crashing. I have traced it down to URLByAppendingPathComponent and can reproduce the crash.

This may also crash on osx. I haven't checked.

Steps to Reproduce:
Run the attached snippet.

Expected Results:
I expect to run the attached snipped without it crashing.

Actual Results:
Run the attached snippet always triggers a crash.

Version:
iOS 7.0.4.
Xcode 5.0.2

Configuration:
The attached snippet crashes both on the device and in the iPhone simulator. 

It crashes in both the 32bit simulator and the 64bit simulator.

It crashes on my iPhone5S. 

--------------
//
//  main.m
//  Created by Simon Strandgaard on 2014/01/25.
//  Copyright 2014 opcoders.com. All rights reserved.
//

#import <Foundation/Foundation.h>

NSData *DataFromHex(NSString* hexString) {
	NSString *s = [hexString stringByReplacingOccurrencesOfString:@" " withString:@""];
	NSMutableData *data= [[NSMutableData alloc] init];
	unsigned char whole_byte;
	char byte_chars[3] = {'\0','\0','\0'};
	for (int i = 0; i < ([s length] / 2); i++) {
		byte_chars[0] = [s characterAtIndex:i*2];
		byte_chars[1] = [s characterAtIndex:i*2+1];
		whole_byte = strtol(byte_chars, NULL, 16);
		[data appendBytes:&whole_byte length:1];
	}
	return data;
}

int main(int argc, char *argv[]) {
    @autoreleasepool {
		NSString *hex = @"fffe3100 3cd87adf 3dd891dc 3dd83ade 3dd868dc 3dd88bdc 3dd82e00 74007200 64007200";
		NSString *evilPathComponent = [[NSString alloc] initWithData:DataFromHex(hex) encoding:NSUTF16StringEncoding];
		NSURL *url = [NSURL URLWithString:@"file:///dir0/dir1"];
		NSURL *result = [url URLByAppendingPathComponent:evilPathComponent]; // EXC_BAD_ACCESS
		NSLog(@"We never gets here: %@", result);
		return EXIT_SUCCESS;
	}
}