Fix bug when shading ScalaLongSignature

[jamiees2]

When shading a @ScalaLongSignature(bytes = Array()), ASM calls visit() for each item in the bytes array, and then calls visitEnd() for each time visit() was called as well.

In visitEnd() we write the rewritten ScalaLongSignature completely, so this causes jarjar-abrams to write the ScalaLongSignature multiple times.

When reflecting on one of these classes, we get an error:

java.lang.annotation.AnnotationFormatError: Duplicate annotation for class: interface scala.reflect.ScalaLongSignature: @scala.reflect.ScalaLongSignature(

A decompilation of the affected class shows that the class is annotated multiple times with @scala.reflect.ScalaLongSignature .

This fixes the issue by making sure we only call rewriteAnnotation once for the lifetime of the class. I tested this, and it solved the issue :)

I imagine the issue wasn't caught earlier because running into this requires you to reflect/use typetags on very very large scala classes which have been rewritten by jarjar-abrams, which is likely rare.

[eed3si9n]

Thanks!

[jamiees2]

When possible, could you release a new version to Maven which I can rebuild https://github.com/jamiees2/jarjar-abrams-cli off of? :)

[eed3si9n]

https://github.com/eed3si9n/jarjar-abrams/releases/tag/v0.3.1 is on its way to Maven Central