391405 - mid-air collisions not detected when submitting attachment details

Status: RESOLVED DUPLICATE of bug 99215

(Bugzilla :: Creating/Changing Bugs, defect)

Description

[Nelson Bolyard (seldom reads bugmail)]

Seen on b.m.o
I received a review request on a patch.  So I went to the bug, clicked
on the "details" link for the patch, spent about 20 minutes writing a 
review and setting the review flag on the attachment details page, and 
then I clicked submit.

While I had been writing that review, the author of the patch found a bug
in the patch I was reviewing, and submitted another patch, and marked the
patch I was reviewing obsolete, which cancelled the review request to me
as well as to another reviewer.  But I did not know any of that had happened.

So, when I submitted my review, submitting the contents of the details
page, I effectively undid his recent changes.  My submission removed the
obsolete flag from the patch I reviewed, and it restored the review request
to the other reviewer for the patch I had reviewed.  I received no warning
from the b.m.o web server about any of this.  

I learned about the collision when I received the email from b.m.o, telling
me of the changes I had made.  There I saw that it appeared at I had 
unobsoleted the patch, and that I had requested that another reviewer 
also review that patch.  So, I went back and corrected it.  But I was 
surely surprised by all this. 

It seems to me that such "mid-air" collisions must be detected and some 
reasonable resolution must be made availbable, one which does not lose 
the reviewers review comments.