Prevent NullPointerException by not setting the static instance

[Codeintheory]

until registration is complete

Description

The Glide instance is not completely thread safe as another thread may get an instance which have not had the components registered

Motivation and Context

With the current code, Thread 2 may get a glide instance because this.glide != null, but registration in Thread 1 has not completed yet

Thread 1- (Does initialization)
GlideApp.with(context).load().into(imageView);

Thread 2-
Loader loader = Glide.get(context).getLoaderFactory().buildModelLoader(modelClass, resourceClass);
Glide.with(mAppContext)
.using(modelLoader, OrbResource.class)
.from(OrbModel.class)

06-21 14:54:44.301: E/AndroidRuntime(29121): java.lang.NullPointerException: ModelLoader must not be null
06-21 14:54:44.301: E/AndroidRuntime(29121): at com.bumptech.glide.provider.FixedLoadProvider.(FixedLoadProvider.java:28)
06-21 14:54:44.301: E/AndroidRuntime(29121): at com.bumptech.glide.GenericTranscodeRequest.build(GenericTranscodeRequest.java:42)
06-21 14:54:44.301: E/AndroidRuntime(29121): at com.bumptech.glide.GenericTranscodeRequest.(GenericTranscodeRequest.java:60)
06-21 14:54:44.301: E/AndroidRuntime(29121): at com.bumptech.glide.RequestManager$GenericModelRequest$GenericTypeRequest.as(RequestManager.java:768)
etc...

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[coveralls]

Coverage increased (+0.003%) to 83.348% when pulling 71f3c8f on Codeintheory:init into 0349ac3 on bumptech:3.0.

[Codeintheory]

Completed the license agreement

[TWiStErRob]

nice catch!

[Codeintheory]

The same bug is in the 4.0 branch as well as I see two, btw

[sjudd]

Nice catch, thanks!

We'll either have to change the interface in Glide v4 or do something more complicated since the Glide object isn't passed in to the Module in v4.

[sjudd]

Also license agreement still seems to be pending.

[TWiStErRob]

@sjudd same fix would work, all we need is glide = initGlide(context); so the read/write/sync is in the same block and not a side effect in the middle of a method. Or you would expect (=allow?!) registerComponents to call Glide.get(context)?

[Codeintheory]

I changed commit to include email as per the requirements of the CLA. Waiting for pending license agreement. Thx

[coveralls]

Coverage increased (+0.003%) to 83.348% when pulling 2f1820c on Codeintheory:init into 0349ac3 on bumptech:3.0.

[sjudd]

@Codeintheory can you double check the cla? Not sure what's up with the bot, but when I look for the email address in the commit or your username it doesn't find anything. Sorry for the inconvenience...

[sjudd]

I'd love to get this in, but still waiting on the cla, @Codeintheory is there some other email address that I should check?

[Codeintheory]

@sjudd I've updated my google CLA to match the email with github account. Please check again for codeinthoery@yahoo.com. Thx

[googlebot]

CLAs look good, thanks!