Description of problem:
Version-Release number of selected component (if applicable):
v3.8.10-1 on devel server.
Steps to Reproduce:
1.Click 'testing - new case' link to enter create case page.
2.Input Summary, then click save btn.
system still stay the current page, that is, system can not save the case and there is no warnings.
when input estimated_time as null, system will save the case's estimated_time as 0.
The above issue also happened when edit case.
verify this issue on 3.8.10-1 on devel server.--->Pass
verify steps are same as description.