Summary

When the user has configured a Select list (Single Choice) custom field with options containing the character "İ" (eg. Azerbaijani or Turkish language), JIRA will throw an error when attempting to search for the option.

Steps to Reproduce

1. Create a new Select list (Single Choice) custom field named DEMO.
2. Add the character "İ" as a new option. Eg. "Problem with İ".
3. Associate the custom field with the issue screens.
4. Create a new test issue with this option "Problem with İ" for DEMO.
5. Go to the Issue navigator and search for: DEMO = "Problem with İ".

Expected Results

The issue navigator will return the issues with "Problem with İ" selected for DEMO.

Actual Results

No issues are returned and JIRA throws the error "The option 'Problem with İ' for field 'DEMO' does not exist."

HAR file indicates response code 400 and "jqlTooComplex" error:

 "request": {
          "method": "POST",
          "url": "https://localhost/secure/QueryComponent!Jql.jspa",
...
  {
              "name": "origin",
              "value": "https://localhost"
            },
            {
              "name": "referer",
              "value": "https://localhost/issues/?jql=DEMO%20%3D%20%22%C4%B0%22
...
 },
        "response": {
          "status": 400,
...
 "cookies": [],
          "content": {
            "size": 47,
            "mimeType": "application/json",
            "text": "{\"errorMessages\":[\"jqlTooComplex\"],\"errors\":{}}"

Workaround

If possible, replace "İ" character within field options with "I" or "i".

Notes

Tested it with the Dfile.encoding=utf-8 and -Dsun.jnu.encoding=UTF-8 startup parameters therefore it does not seem to be an encoding issue.