A DESCRIPTION OF THE PROBLEM :
The program below gives an error when compiled under Java 8, no errors when compiled under Java 6
The error under Java 8 is:
Incompatible types. Found: 'java.util.List<C>', required: 'java.util.List<capture<? extends B>>'
Incompatible types. Found: 'java.util.List<B>', required: 'java.util.List<capture<? extends B>>'

import java.util.ArrayList;
import java.util.List;
import com.google.common.base.Function;
import com.google.common.collect.FluentIterable;

class B { }
class C extends B { }
class D { }

class Test {
    void test() {
        List<B> lb = new ArrayList<B>();
        List<C> lc = new ArrayList<C>();
        
        // compiler error under Java 8, no error under Java 6
        FluentIterable.from(lb == null ? lc : lb).transform(new Function<B, D>() {
            @Override
            public D apply(B b) {
                return null;
            }
        });
    }
}

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile the program in the description under Java 8 and there is a compilation error. Under Java 6 no such error.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No compilation error under Java 8 because Java code is supposed to be backward compatible. Alternatively, kindly, specify the reference why it does not compile.
ACTUAL -
Compilation error under Java 8:
Incompatible types. Found: 'java.util.List<C>', required: 'java.util.List<capture<? extends B>>'
Incompatible types. Found: 'java.util.List<B>', required: 'java.util.List<capture<? extends B>>'

---------- BEGIN SOURCE ----------
import java.util.ArrayList;
import java.util.List;
import com.google.common.base.Function;
import com.google.common.collect.FluentIterable;

class B { }
class C extends B { }
class D { }

class Test {
    void test() {
        List<B> lb = new ArrayList<B>();
        List<C> lc = new ArrayList<C>();
        
        // compiler error under Java 8, no error under Java 6
        FluentIterable.from(lb == null ? lc : lb).transform(new Function<B, D>() {
            @Override
            public D apply(B b) {
                return null;
            }
        });
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
If this is the correct behavior under Java 8, kindly sepcify what has changed compared with Java 6.

FREQUENCY : always