NSLocalizedString auto load Base.lproj if key not found

NSLocalizedString+Base.m

#ifndef L
#define L(key) [NSBundle.mainBundle localizedStringForKey:(key)]
#endif

@interface NSBundle (NSLocalizedString_Base)
- (NSString *)localizedStringForKey:(NSString *)key;
@end

@implementation NSBundle (NSLocalizedString_Base)

- (NSString *)localizedStringForKey:(NSString *)key {
    NSString * s = [self localizedStringForKey:key value:@"" table:nil];
    if ([s isEqualToString:key]) {
        NSString * path = [[NSBundle mainBundle] pathForResource:@"Base" ofType:@"lproj"];
        NSBundle * languageBundle = [NSBundle bundleWithPath:path];
        s = [languageBundle localizedStringForKey:key value:@"" table:nil];
    }
    if (s == nil) {
        s = key;
    }
    return s;
}

@end