Bug fix: 769. The main reason is that the complexity of countOccurrences is...

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import it.niedermann.owncloud.notes.R;

public abstract class SearchableBaseNoteFragment extends BaseNoteFragment {

    }

    private static int countOccurrences(String haystack, String needle) {

        if (haystack == null || haystack.isEmpty() || needle == null || needle.isEmpty()) {

            return 0;

        }

        int lastIndex = 0;

        int count = 0;

        Matcher m = Pattern.compile(needle, Pattern.CASE_INSENSITIVE | Pattern.LITERAL)

                .matcher(haystack);

        while (lastIndex != -1) {

            lastIndex = haystack.toLowerCase().indexOf(needle.toLowerCase(), lastIndex);

            if (lastIndex != -1) {

        int count = 0;

        while (m.find()) {

            count++;

                lastIndex += needle.length();

            }

        }

        return count;

    }