Incorrect objectForKey results for keys not in table.

[omarkilani]

Hi John,

There's a bug in _JKDictionaryHashTableEntryForKey which returns an incorrect result (returns an object when it should return NULL) if the key falls into the same bucket as another key, but the hash and value don't match.

The loop does:

atEntry = &dictionary->entry[(keyEntry + idx) % dictionary->capacity];

But never clears atEntry if we get to the end of the loop and the key wasn't found.

Thanks!

Regards,
Omar

[johnezang]

This was reported by another user, but I never heard back if the fix I gave them worked. I've checked in that fix.

If you happen to have some JSON that tickles this bug, could you paste it in to the ticket? This condition never showed up during my testing, it requires just the right set of conditions that's almost impossible to create by hand.

[omarkilani]

The JSON:

{"l1":1,"l2":2,"l3":3}

Will reproduce this issue, and return the value for 'l2' if you request the value for 'l4'.

Sample code:

#import <Foundation/Foundation.h>
#import "JSONKit.h"

int main(int argc, char *argv[]) {
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
  NSDictionary *dict = [@"{\"l1\":1,\"l2\":2,\"l3\":3}" objectFromJSONString];
  NSLog(@"dict = %@", dict);
  NSLog(@"objectForKey:l4 = %@", [dict objectForKey:@"l4"]);
  [pool release];
  return(0);
}

Sample output:

2011-03-12 14:10:42.352 main[45328:903] dict = {
    l1 = 1;
    l2 = 2;
    l3 = 3;
}
2011-03-12 14:10:42.355 main[45328:903] objectForKey:l4 = 2

Hope this helps!