Risk of overwriting issue information during concurrent editing

[sk-ys]

Under the current specification, if someone else updates an issue while you are editing it, the issue information in the edit area may be forcibly overwritten. I think it might be necessary to take measures such as issuing a warning and displaying the updated areas before overwriting if you were in the middle of editing.
What do you think?

[MayamaTakeshi]

That was a bug. I have added a commit to force detection of the conflict (fields in the Edit box should not be updated).
However at the moment, the conflict warning doesn't show the conflicting fields.

[MayamaTakeshi]

I have added another commit that I believe solves this issue.

[sk-ys]

Thank you for your response.
I'm sorry. I'll chelk it this weekend.

[sk-ys]

I have checked your update.
I understand that halting updates to the editing form will allow it to function similarly to the original Redmine.
However, the conflict confirmation screen will no longer appear when others update issues in the following order:

1. Update items that are subject to conflict confirmation (journals with the 'has-detailes' class).
2. Update journal notes only (journals without the 'has-detailes' class).

Once a conflict occurs during the issue page is open, I think it is necessary to ensure that lock_version is not automatically updated thereafter. Other than that, everything seems fine.

Furthermore, I am considering that there would be no problem with updating the editing form as before your commit if the user has not edited the entire form or a specific item.

[sk-ys]

I have tried to address the issue of the conflict confirmation screen not showing up if there are no details on the last update.
sk-ys@9c4ce95

[sk-ys]

I have added support for updates per attribute in issue form. Please confirm.
sk-ys@48914cc

[MayamaTakeshi]

Thanks. PR created and merged as #55.
(also, created #56)