Program: 13013
Project: 13013
Buggy source:
public void visitTopLevel(JCCompilationUnit tree){
  JavaFileObject prev=log.useSource(tree.sourcefile);
  boolean addEnv=false;
  boolean isPkgInfo=tree.sourcefile.isNameCompatible("String_Node_Str",JavaFileObject.Kind.SOURCE);
  if (tree.pid != null) {
    tree.packge=reader.enterPackage(TreeInfo.fullName(tree.pid));
    if (tree.packageAnnotations.nonEmpty()) {
      if (isPkgInfo) {
        addEnv=true;
      }
 else {
        log.error(tree.packageAnnotations.head.pos(),"String_Node_Str");
      }
    }
  }
 else {
    tree.packge=syms.unnamedPackage;
  }
  tree.packge.complete();
  Env<AttrContext> env=topLevelEnv(tree);
  if (isPkgInfo) {
    Env<AttrContext> env0=typeEnvs.get(tree.packge);
    if (env0 == null) {
      typeEnvs.put(tree.packge,env);
    }
 else {
      JCCompilationUnit tree0=env0.toplevel;
      if (!fileManager.isSameFile(tree.sourcefile,tree0.sourcefile)) {
        log.warning(tree.pid != null ? tree.pid.pos() : null,"String_Node_Str",tree.packge);
        if (addEnv || (tree0.packageAnnotations.isEmpty() && tree.docComments != null && tree.docComments.get(tree) != null)) {
          typeEnvs.put(tree.packge,env);
        }
      }
    }
    for (Symbol q=tree.packge; q != null && q.kind == PCK; q=q.owner)     q.flags_field|=EXISTS;
    Name name=names.package_info;
    ClassSymbol c=reader.enterClass(name,tree.packge);
    c.flatname=names.fromString(tree.packge + "String_Node_Str" + name);
    c.sourcefile=tree.sourcefile;
    c.completer=null;
    c.members_field=new Scope(c);
    tree.packge.package_info=c;
  }
  classEnter(tree.defs,env);
  if (addEnv) {
    todo.append(env);
  }
  log.useSource(prev);
  result=null;
}

Fixed version (ground truth):
@Override public void visitTopLevel(JCCompilationUnit tree){
  JavaFileObject prev=log.useSource(tree.sourcefile);
  boolean addEnv=false;
  boolean isPkgInfo=tree.sourcefile.isNameCompatible("String_Node_Str",JavaFileObject.Kind.SOURCE);
  if (tree.pid != null) {
    tree.packge=reader.enterPackage(TreeInfo.fullName(tree.pid));
    if (tree.packageAnnotations.nonEmpty()) {
      if (isPkgInfo) {
        addEnv=true;
      }
 else {
        log.error(tree.packageAnnotations.head.pos(),"String_Node_Str");
      }
    }
  }
 else {
    tree.packge=syms.unnamedPackage;
  }
  tree.packge.complete();
  Env<AttrContext> topEnv=topLevelEnv(tree);
  if (isPkgInfo) {
    Env<AttrContext> env0=typeEnvs.get(tree.packge);
    if (env0 == null) {
      typeEnvs.put(tree.packge,topEnv);
    }
 else {
      JCCompilationUnit tree0=env0.toplevel;
      if (!fileManager.isSameFile(tree.sourcefile,tree0.sourcefile)) {
        log.warning(tree.pid != null ? tree.pid.pos() : null,"String_Node_Str",tree.packge);
        if (addEnv || (tree0.packageAnnotations.isEmpty() && tree.docComments != null && tree.docComments.get(tree) != null)) {
          typeEnvs.put(tree.packge,topEnv);
        }
      }
    }
    for (Symbol q=tree.packge; q != null && q.kind == PCK; q=q.owner)     q.flags_field|=EXISTS;
    Name name=names.package_info;
    ClassSymbol c=reader.enterClass(name,tree.packge);
    c.flatname=names.fromString(tree.packge + "String_Node_Str" + name);
    c.sourcefile=tree.sourcefile;
    c.completer=null;
    c.members_field=new Scope(c);
    tree.packge.package_info=c;
  }
  classEnter(tree.defs,topEnv);
  if (addEnv) {
    todo.append(topEnv);
  }
  log.useSource(prev);
  result=null;
}