No results found when search query is longer than 256 characters

When I pass search query LONGER THAN 256 characters, search results in empty search page (no results found).
The search query is passed through GET method .../dosearchsite.action?where=TEST&type=page&queryString=...

• POST request method did not help either - behavior is the same.

Example queries - first which is shorter than 256 characters - works fine, second which is longer - doesn't work:

ancestorIds:(29658282 OR 29658159 OR 29658142 OR 29658019 OR 29657896 OR 29657773 OR 29657650 OR 29657527 OR 29657404 OR 29657231 OR 29657090 OR 28543102 OR 28542832 OR 28542603 OR 28542562 OR 28542024 OR 28541754 OR 28541484) AND labelText:"label1"

ancestorIds:(29658405 OR 29658282 OR 29658159 OR 29658142 OR 29658019 OR 29657896 OR 29657773 OR 29657650 OR 29657527 OR 29657404 OR 29657231 OR 29657090 OR 28543102 OR 28542832 OR 28542603 OR 28542562 OR 28542024 OR 28541754 OR 28541484) AND labelText:"label1"

Steps to reproduce:
1. Put together search query that is longer than 256 characters
2. Search Confluence with your query .../dosearchsite.action?where=TEST&type=page&queryString=...

Expected behavior:
found pages (or at least if search is somehow limited inform user about this limit by some kind of warning message...)

What happened instead:
No results found

Question posted on Atlassian forum:
https://answers.atlassian.com/questions/267479/is-there-a-length-limitation-of-search-query-in-confluence-5-4-3