Why does clearing NSUserDefaults cause EXC_CRASH later when creating a UIWebView?

Question

Before I begin, I should tell you that this only happens in iOS 5.1. Before the most recent update, this had never happened and it still does not happen on any othe

Answer 1

I'm seeing this issue as well, I think you have to have created a UIWebView first before clearing user defaults for it to occur. A clean project with the following will cause the crash in iOS5.1, this works fine in iOS5.0 and earlier:

UIWebView *webView = [[UIWebView alloc] init];
[webView release];

[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

UIWebView *anotherWebView = [[UIWebView alloc] init];
[anotherWebView release];

I can work around the crash by doing this instead, which avoids having to remember all your settings keys:

id workaround51Crash = [[NSUserDefaults standardUserDefaults] objectForKey:@"WebKitLocalStorageDatabasePathPreferenceKey"];
NSDictionary *emptySettings = (workaround51Crash != nil)
                ? [NSDictionary dictionaryWithObject:workaround51Crash forKey:@"WebKitLocalStorageDatabasePathPreferenceKey"]
                : [NSDictionary dictionary];
[[NSUserDefaults standardUserDefaults] setPersistentDomain:emptySettings forName:[[NSBundle mainBundle] bundleIdentifier]];

Anyone see any issues with doing it this way?