When JIRA is being used for issue management along with Phabricator controlled VCS (internal or external) it's a common practice to place JIRA issue keys into commit messages to indicate association of these commits to particular issue(-s).
There is also `JIRA Issues` field (I guess it's only visible if I enabled JIRA as Authentication Provider), when creating new Differential revision, which could make use of that practice.
How I see this working:
# makes changes in `ArcanistDiffWorkflow::parseCommitMessagesIntoFields` method
# look at message of each given commit for JIRA issue keys
# if found, then add `\nJIRA Issues: {issue key1}, {issue key2}, ... {issue keyN}` to the end of commit message
Of what I'm unsure is:
# what if there are 2+ commits and each of them has issue key in them, then which commit message will be scanned to fill in the new/existing Differential Revision template that is shown after that
# how do determine, that JIRA integration is enabled and this issue key lookup should be applied
I'm willing to implement this.