Simultaneous editing can couse unwanted changes

#1

Observed Behavior:
Unwanted deletion of assigned persone “Assigned To” field with no error or worning by editing the task

Expected Behavior:
User One would get a wornig about unwanted changes( deleting pesrone from “Assigned To” field )

Phabricator Version:
phabricator 99c1491cf5823c9e95b2f49cce6da4218e0b2bca (Sat, Mar 30) (branched from 02f94cd7d2885de502d03934af3a0c24453e8e58 on origin)
arcanist 4d22e0f89f10b8a7f47f6ee615e0ccf0f354e582 (Mar 8 2019) (branched from 9830c9316d38988b2dc283ac1a124b73bc8e6c5f on origin)
phutil e9bbfcb1435375919d1d2ac4cb4ce48cff0295cb (Sat, Mar 30) (branched from 524fcf465108216bf2fa6126473873ab8e42360a on origin)
php 5.5.9-1
ubuntu4.27
diff 3.3 at /usr/bin/diff
git 1.9.1 at /usr/bin/git
hg Not Available
pygmentize 1.6 at /usr/bin/pygmentize
svn Not Available

Reproduction Steps:
User One opens maniphest task for editing and making changes
User Two Assigning someone for this task
User One Saving changes
Any assigned persone would be deleted from “Assigned To” field with no error or worning
Only small message in task history

#2

This is upstreamed and not really a ‘bug’, the software just lacks conflict detection in (most, not all) places.

https://secure.phabricator.com/T4768

closed #3