Bug 209145 – [Cocoa] Crash under -[WKPreferenceObserver init]

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[Per Arne Vollan]

A crash has been observed on line 206 in PreferenceObserver.mm:

204 	    for (auto domain : domains) {
205 	        auto userDefaults = adoptNS([[WKUserDefaults alloc] initWithSuiteName:domain]);
-> 206 	        userDefaults.get()->m_observer = self;

[Per Arne Vollan]

rdar://problem/60470713

[Per Arne Vollan]

Created attachment 393667 [details]
Patch

[Darin Adler]

Comment on attachment 393667 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=393667&action=review

> Source/WebKit/UIProcess/Cocoa/PreferenceObserver.mm:206
> -        auto userDefaults = adoptNS([[WKUserDefaults alloc] initWithSuiteName:domain]);
> +        auto userDefaults = adoptNS([WKUserDefaults alloc]);
> +        if (![userDefaults initWithSuiteName:domain]) {

This is the wrong way to write it. Leave the code as is and write it like this:

    auto userDefaults = adoptNS([[WKUserDefaults alloc] initWithSuiteName:domain]);
    if (!userDefaults) {

The adoptNS function already handles everything correctly.

[Per Arne Vollan]

(In reply to Darin Adler from comment #3)
> Comment on attachment 393667 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=393667&action=review
> 
> > Source/WebKit/UIProcess/Cocoa/PreferenceObserver.mm:206
> > -        auto userDefaults = adoptNS([[WKUserDefaults alloc] initWithSuiteName:domain]);
> > +        auto userDefaults = adoptNS([WKUserDefaults alloc]);
> > +        if (![userDefaults initWithSuiteName:domain]) {
> 
> This is the wrong way to write it. Leave the code as is and write it like
> this:
> 
>     auto userDefaults = adoptNS([[WKUserDefaults alloc]
> initWithSuiteName:domain]);
>     if (!userDefaults) {
> 
> The adoptNS function already handles everything correctly.

Fixed.

Thanks for reviewing!

[Per Arne Vollan]

Committed r258515: <https://trac.webkit.org/changeset/258515/webkit>