FULL PRODUCT VERSION :
java version "1.7.0_03"
Java(TM) SE Runtime Environment (build 1.7.0_03-b04)
Java HotSpot(TM) 64-Bit Server VM (build 22.1-b02, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux PC1374 3.0.0-16-generic #28-Ubuntu SMP Fri Jan 27 17:44:39 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
Compiler throws a NullPointerException in Resolve.isAccessible when a package-prive class is used in (at least) generics of a public class (see source).

REGRESSION. Last worked in version 6u29

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Use source delivered, and compile using:

javac -source 1.7 -target 1.7 -encoding utf-8 data/Dto.java data/Dao.java wicket/BugTest.java

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Compiler delivers a readable warning that the (abstract) class Dto should be visible for use in Dao<V extends Dto>

or; should this be legal (I'm doubting that, since Dto would be referenced in Dao to the outside world?); just compile everything.
ACTUAL -
NullPointerException (see Error message)

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.NullPointerException
at com.sun.tools.javac.comp.Resolve.isAccessible(Resolve.java:162)
at com.sun.tools.javac.comp.Resolve.isAccessible(Resolve.java:216)
at com.sun.tools.javac.comp.Resolve.isAccessible(Resolve.java:212)
at com.sun.tools.javac.comp.Resolve$AccessError.getDiagnostic(Resolve.java:2260)
at com.sun.tools.javac.comp.Resolve.logResolveError(Resolve.java:1822)
at com.sun.tools.javac.comp.Resolve.logAccessError(Resolve.java:1812)
at com.sun.tools.javac.comp.TransTypes.cast(TransTypes.java:110)
at com.sun.tools.javac.comp.TransTypes.coerce(TransTypes.java:126)
at com.sun.tools.javac.comp.TransTypes.retype(TransTypes.java:160)
at com.sun.tools.javac.comp.TransTypes.visitApply(TransTypes.java:601)
at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1321)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.TransTypes.translate(TransTypes.java:425)
at com.sun.tools.javac.comp.TransTypes.translateArgs(TransTypes.java:190)
at com.sun.tools.javac.comp.TransTypes.visitApply(TransTypes.java:598)
at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1321)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.TransTypes.translate(TransTypes.java:425)
at com.sun.tools.javac.comp.TransTypes.visitExec(TransTypes.java:564)
at com.sun.tools.javac.tree.JCTree$JCExpressionStatement.accept(JCTree.java:1167)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitBlock(TreeTranslator.java:160)
at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:781)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.TransTypes.translate(TransTypes.java:425)
at com.sun.tools.javac.comp.TransTypes.visitMethodDef(TransTypes.java:459)
at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:669)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitClassDef(TreeTranslator.java:134)
at com.sun.tools.javac.comp.TransTypes.translateClass(TransTypes.java:871)
at com.sun.tools.javac.comp.TransTypes.visitClassDef(TransTypes.java:446)
at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:591)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
at com.sun.tools.javac.tree.TreeTranslator.visitClassDef(TreeTranslator.java:134)
at com.sun.tools.javac.comp.TransTypes.translateClass(TransTypes.java:871)
at com.sun.tools.javac.comp.TransTypes.visitClassDef(TransTypes.java:446)
at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:591)
at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
at com.sun.tools.javac.comp.TransTypes.translate(TransTypes.java:425)
at com.sun.tools.javac.comp.TransTypes.translateTopLevelClass(TransTypes.java:898)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1375)
at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1271)
at com.sun.tools.javac.main.JavaCompiler.compile2(JavaCompiler.java:870)
at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:829)
at com.sun.tools.javac.main.Main.compile(Main.java:419)
at com.sun.tools.javac.main.Main.compile(Main.java:333)
at com.sun.tools.javac.main.Main.compile(Main.java:324)
at com.sun.tools.javac.Main.compile(Main.java:76)
at com.sun.tools.javac.Main.main(Main.java:61)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
// -- FILE: data/Dto.java

package data;

abstract class Dto { }

// -- FILE: data/Dao.java

package data;

public abstract class BugDao<V extends Dto> {
  public void delete(V dto) { }
  
  public static class TestDto extends Dto { }

  public static class TestDao extends BugDao<TestDto> { }
}

// -- FILE: bug/BugTest.java

package bug;

import data.BugDao.TestDao;
import data.BugDao.TestDto;

public class BugTest {
  private TestDao dao;

  public void test(Test<TestDto> obj) {
    dao.delete(obj.getObject());
  }

  public static class Test<T> {
    public T getObject() {
      return null;
    }
  }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
make type Dto (data/Dto.java) public, instead of package-private (default)