Issue Summary

This is reproducible on Data Center: (yes)

If you have a custom field of type checkbox and if it is configured to have one of the options  "checked" by default, using Issues -> "Import Issues from CSV" to import issues will cause the option to be "checked" even if the custom field value is left blank/null in the CSV import file.

Steps to Reproduce

1. Create a custom field of type checkboxes(say checks), create a default value(say option1) for this field, and configure it to be “checked” by default.
2. Add this custom field to the create issue screen.
3. Create a CSV file to supply as an input for the “Import Issues from CSV” step. Here, the Custom field (checks) is our custom field. The value for “Custom field (checks)” needs to be blank so that the option will not be selected (expected behavior)

4. 0	Summary	Description	Issue type	Components	Issue id	Parent id	Custom field (Epic link)	Custom field (checks)
   1	Test	Test	Story		8		TEST-35

5. From the top navigation bar, select “Import Issues from CSV” from the "Issues" dropdown
6. Attach the file created in Step #3 for “CSV Source File”
7. Click on “Next” and select the project to which you want to import the issues.
8. Click on “Next”, In the “Map fields” screen, map the fields appropriately, including the Custom field (checks) to the custom field we created in step #1
9. Click on “Begin Import”.

Expected Results

On the imported issue, the customfield "checks" will not have the option(option1) selected as the value was left blank in the CSV import.

Actual Results

However, it is observed that the customfield "checks" will have the option(option1) selected.

Workaround

Use System -> "External System Import" to import the issues, however, this would require Admin rights.