Method head

app/src/main/java/eu/faircode/email/HtmlHelper.java:507–520

(Node node, int depth)

                private boolean remove = false;

                @Override
                public FilterResult head(Node node, int depth) {
                    if (node instanceof Comment) {
                        String data = ((Comment) node).getData().trim();
                        if (data.startsWith("[if") && !data.endsWith("endif]")) {
                            remove = true;
                            return FilterResult.REMOVE;
                        } else if (remove && data.endsWith("endif]")) {
                            remove = false;
                            return FilterResult.REMOVE;
                        }
                    }
                    return (remove ? FilterResult.REMOVE : FilterResult.CONTINUE);
                }

                @Override
                public FilterResult tail(Node node, int depth) {