[Cocoa] Return early from preference change notification handler if t…

…here is no observer

https://bugs.webkit.org/show_bug.cgi?id=213050

Reviewed by Darin Adler.

Currently, the observer member is checked inside the loop iterating over all the keys,
but this check should be moved outside of the loop.

No new tests, since this is not a change in behavior.

* UIProcess/Cocoa/PreferenceObserver.mm:
(-[WKUserDefaults _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]):


Canonical link: https://commits.webkit.org/225834@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@262865 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebKit/ChangeLog

@@ -1,3 +1,18 @@
+2020-06-10  Per Arne Vollan  <pvollan@apple.com>
+
+        [Cocoa] Return early from preference change notification handler if there is no observer
+        https://bugs.webkit.org/show_bug.cgi?id=213050
+
+        Reviewed by Darin Adler.
+
+        Currently, the observer member is checked inside the loop iterating over all the keys,
+        but this check should be moved outside of the loop.
+
+        No new tests, since this is not a change in behavior.
+
+        * UIProcess/Cocoa/PreferenceObserver.mm:
+        (-[WKUserDefaults _notifyObserversOfChangeFromValuesForKeys:toValuesForKeys:]):
+
 2020-06-10  Brady Eidson  <beidson@apple.com>
 
         Crash growing a CFData with incremental PDF loading.

Source/WebKit/UIProcess/Cocoa/PreferenceObserver.mm

@@ -49,6 +49,9 @@ - (void)_notifyObserversOfChangeFromValuesForKeys:(NSDictionary<NSString *, id>
 {
     [super _notifyObserversOfChangeFromValuesForKeys:oldValues toValuesForKeys:newValues];
 
+    if (!m_observer)
+        return;
+
     for (NSString *key in oldValues) {
         id oldValue = oldValues[key];
         id newValue = newValues[key];
@@ -68,9 +71,6 @@ - (void)_notifyObserversOfChangeFromValuesForKeys:(NSDictionary<NSString *, id>
             encodedString = [data base64EncodedStringWithOptions:0];
         }
 
-        if (!m_observer)
-            return;
-
         auto globalValue = adoptCF(CFPreferencesCopyValue((__bridge CFStringRef)key, kCFPreferencesAnyApplication, kCFPreferencesCurrentUser, kCFPreferencesAnyHost));
         auto domainValue = adoptCF(CFPreferencesCopyValue((__bridge CFStringRef)key, (__bridge CFStringRef)m_suiteName, kCFPreferencesCurrentUser, kCFPreferencesAnyHost));