jql=TestCaseSetUID%20~%20XXX-TC-5700

import com.atlassian.jira.bc.issue.search.SearchService

import com.atlassian.jira.component.ComponentAccessor

import com.atlassian.jira.user.ApplicationUser

import com.atlassian.jira.jql.builder.JqlQueryBuilder;

import com.atlassian.jira.web.bean.PagerFilter

import com.atlassian.jira.issue.search.SearchResults;

import com.atlassian.jira.issue.fields.CustomField;

import com.atlassian.jira.issue.CustomFieldManager

ApplicationUser user = ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser();

SearchService searchService = ComponentAccessor.getComponentOfType(SearchService.class);

CustomFieldManager jiraCustomFieldManager = ComponentAccessor.getComponentOfType(CustomFieldManager.class);

JqlQueryBuilder builder = JqlQueryBuilder.newBuilder();

CustomField customField =

  jiraCustomFieldManager.getCustomFieldObjectByName("TestCaseSetUID");

// OK using jira

// jql=TestCaseSetUID%20~%20XXX-TC-5700

// Wrong

def query = builder

 .where()

.customField(customField.getIdAsLong())

.eq("XXX-TC-5700")

.buildQuery()

;

SearchResults results = searchService.search(user, 

           query,

           PagerFilter.getUnlimitedFilter());

results.getIssues() // []