NSPredicate: Check if predicates with NSNull work as expected

Tests/base/NSPredicate/nsnull.m

@@ -0,0 +1,34 @@
+#import "ObjectTesting.h"
+#import "Foundation/NSAutoreleasePool.h"
+#import "Foundation/NSPredicate.h"
+#import "Foundation/NSArray.h"
+#import "Foundation/NSNull.h"
+
+int main(void) {
+    NSAutoreleasePool *arp = [NSAutoreleasePool new];
+	NSArray *array, *filtered;
+	NSPredicate *predicate;
+
+    // Basic filtering with NSPredicate
+    array = @[@{@"key": @"value1"}, @{@"key": @"value2"}, [NSNull null]];
+	predicate = [NSPredicate predicateWithFormat:@"key == %@", @"value2"];
+    filtered = [array filteredArrayUsingPredicate: predicate];
+
+    PASS(filtered.count == 1 && [filtered[0][@"key"] isEqualToString:@"value2"], 
+         "NSPredicate should correctly filter array including NSNull");
+
+    // Filtering with NSPredicate where no match is found
+	predicate = [NSPredicate predicateWithFormat:@"key == %@", @"nonexistent"];
+    filtered = [array filteredArrayUsingPredicate: predicate];
+    PASS(filtered.count == 0, 
+         "NSPredicate should return an empty array when no match is found");
+
+    // Filtering with NSPredicate with a different key
+	predicate = [NSPredicate predicateWithFormat:@"anotherKey == %@", @"value1"];
+    filtered = [array filteredArrayUsingPredicate: predicate];
+    PASS(filtered.count == 0, 
+         "NSPredicate should return an empty array when filtering with a non-existent key");
+
+    [arp release];
+    return 0;
+}