Created attachment 142512 [details]
stacktrace

I have the exception in the method when I copy-paste fragment:
                        while(cppTokenSequence.moveNext()) {
                        final Token<TokenId> token = cppTokenSequence.token();
                        final TokenId id = token.id();
                        if(id instanceof CppTokenId) {
of the method inside deepest if statement.
This is a text of the method after insertion:

    private TokenItem<TokenId> getTokenStream(final Document doc, final int offset) {
        final AtomicReference<TokenItem<TokenId>> out = new AtomicReference<TokenItem<TokenId>>();
        doc.render(new Runnable() {
            @Override
            public void run() {
                TokenSequence<TokenId> cppTokenSequence = CndLexerUtilities.getCppTokenSequence(doc, offset, true, true);
                if (cppTokenSequence == null) {
                    return;
                }
                if (!cppTokenSequence.language().equals(CppTokenId.languagePreproc())) {
                    return;
                }
                cppTokenSequence.moveStart();
                if (cppTokenSequence.moveNext()) {
                    while(cppTokenSequence.moveNext()) {
                        final Token<TokenId> token = cppTokenSequence.token();
                        final TokenId id = token.id();
                        if(id instanceof CppTokenId) {
                            if (CppTokenId.PREPROCESSOR_KEYWORD_DIRECTIVE_CATEGORY.equals(((CppTokenId)id).primaryCategory())) {
                                if (id == CppTokenId.PREPROCESSOR_LINE) {
                                    final int tokenOffset = cppTokenSequence.offset();
                                    TokenItem res = new TokenItem() {

                                        @Override
                                        public TokenId id() {
                                            return id;
                                        }

                                        @Override
                                        public int offset() {
                                            return tokenOffset;
                                        }

                                        @Override
                                        public CharSequence text() {
                                            return token.text();
                                        }

                                        @Override
                                        public int index() {
                                            return 0;
                                        }

                                        @Override
                                        public int length() {
                                            return text().length();
                                        }

                                        @Override
                                        public PartType partType() {
                                            return null;
                                        }
                                    };
                                    out.set(res);
                        while(cppTokenSequence.moveNext()) {
                        final Token<TokenId> token = cppTokenSequence.token();
                        final TokenId id = token.id();
                        if(id instanceof CppTokenId) {
                                    
                                    return;
                                } else {
                                    return;
                                }
                            }
                        }
                    }
                }
            }
        });
        return out.get();
    }

Created attachment 149003 [details]
stacktrace

edit java file

This bug already has 5 duplicates 
see http://statistics.netbeans.org/exceptions/detail.do?id=205518

Created attachment 149366 [details]
stacktrace

Nullpointer Exception occurred when running

*** Bug 248957 has been marked as a duplicate of this bug. ***

This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue.

Thanks for your cooperation,
NetBeans IDE 8.2 Release Boss