Add some further debug code for _scrollViewDidChangeBounds:

Source/SPObjectAdditions.m

@@ -28,6 +28,9 @@
//
//  More info at <https://github.com/sequelpro/sequelpro>

#import <objc/runtime.h>
static NSMutableDictionary *gScrollViewListeners;

@implementation NSObject (SPObjectAdditions)

/**
@@ -92,7 +95,53 @@ - (void)_scrollViewDidChangeBounds:(id)obj
	
	[msg appendFormat:@"self: %p (class <%@>)\n\n",self,[self className]];
	
	NSString *key = [NSString stringWithFormat:@"snd=%p,obs=%p",obj,self];
	
	[msg appendFormat:@"registration info for pair (%@):\n %@",key,[gScrollViewListeners objectForKey:key]];
	
	@throw [NSException exceptionWithName:NSInternalInconsistencyException reason:msg userInfo:nil];
}

@end


@implementation NSNotificationCenter (SPScrollViewDebug)

+ (void)load
{
	 static dispatch_once_t onceToken;
	
	dispatch_once(&onceToken, ^{
		gScrollViewListeners = [[NSMutableDictionary alloc] init];
		
		Class notificationCenter = [self class];
		
		SEL orig = @selector(addObserver:selector:name:object:);
		SEL exch = @selector(sp_addObserver:selector:name:object:);
		
		Method origM = class_getInstanceMethod(notificationCenter, orig);
		Method exchM = class_getInstanceMethod(notificationCenter, exch);
		
		method_exchangeImplementations(origM, exchM);
	});

}

- (void)sp_addObserver:(id)notificationObserver selector:(SEL)notificationSelector name:(NSString *)notificationName object:(id)notificationSender
{
	if(notificationSelector == @selector(_scrollViewDidChangeBounds:) && [notificationName isEqualToString:NSViewBoundsDidChangeNotification]) {
		NSString *key = [NSString stringWithFormat:@"snd=%p,obs=%p",notificationSender,notificationObserver];
		NSMutableString *val = [NSMutableString string];
		[val appendFormat:@"observer: %1$p (class %2$@) description: %1$@\n",notificationObserver,[notificationObserver className]];
		if([notificationObserver isKindOfClass:[NSView class]]) {
			[val appendFormat:@"  view info: id=%@, tag=%ld\n",[(NSView *)notificationObserver identifier], [(NSView *)notificationObserver tag]];
		}
		[val appendFormat:@"\nbacktrace:\n%@\n\n",[NSThread callStackSymbols]];
		
		[gScrollViewListeners setObject:val forKey:key];
	}
	// not recursive! method is swizzled.
	[self sp_addObserver:notificationObserver selector:notificationSelector name:notificationName object:notificationSender];
}

@end