Annotation processing api returns default modifier for interface without default methods, but with overriden method. Interface modifiers are different when annotation processor is used on class files and source files.

The example sources are attached.

When I process source file
> C:\Java\8b106\windows-i586\bin\javac.exe -classpath C:\work\Oracle\Proc\out\production\Proc -processor jck.proc.Proc C:\work\Oracle\Proc\src\jck\proc\Test.java

everything is fine, the reported modifiers are abstract.

When I use it on class:
C:\Java\8b106\windows-i586\bin\javac.exe -classpath C:\Users\ORA-56284\Dropbox\work\Oracle\Proc\out\production\Proc -processor jck.proc.Proc jck.proc.i2

the reported modifiers are [abstract, default].

Sources attached.