Potential null dereference. According to coding standards in 'Creating and Returning NSError Objects' the parameter 'error' may be null.

[leddo]

Potential null dereference. According to coding standards in 'Creating and Returning NSError Objects' the parameter 'error' may be null.

[yujuan]

In Objective-C a method can only return one value, and this is a typical case where you want to return two. In C-like languages when you need to return an extra value you ask for a pointer to a value of that type. The NSError** pattern is used when a method returns some value but may also want to return an error object (of type NSError*). see ref http://stackoverflow.com/questions/903103/why-does-nserror-need-double-indirection-pointer-to-a-pointer.
So you can ignore these warning

[jameseanthony]

Hi yujuan,

leddo is actually correct that this is a problem in the FBRequest code. The NSError *_'s should be checked against NULL, otherwise calling *error = ... may cause a null dereference and crash. *error = {...} calls should be replaced with if(error != NULL) {_error = {...}}

[yujuan]

The only place that call this function is id result = [self parseJsonResponse:data error:&error]; in the same file which essentially warranty that error is not null from the caller side.

[jameseanthony]

It doesn't cause a crash now, but it causes warnings and isn't robust against future modifications.

[yujuan]

ok, that is good point, I will make this change in the next revision.

[yujuan]

just check in the fix