Can I infer from JRA-22817 that the desired behaviour is to not show this dialog for non-existent users at all?

JRA-22817 is talking about the logged in user not having permissions to see user profile (in particular because the user is anonymous), so this is a different situation.

I would think that the desired behaviour is to include a pop up but let it say "user 'foo' was deleted" or something.

Shortest path fix I see is changing userhover.js to restrict the hover to only happening when the rel attribute is supplied. It looks like this was probably a side-effect of JRADEV-5313, as this used to select on "a.user-hover", so it would not previously have applied to the <span>s.

diff --git a/jira-components/jira-webapp/src/main/webapp/includes/jira/dialog/userhover.js b/jira-components/jira-webapp/src/main/webapp/includes/jira/dialog/userhover.js
index 4b6deb9..e781e98 100644
--- a/jira-components/jira-webapp/src/main/webapp/includes/jira/dialog/userhover.js
+++ b/jira-components/jira-webapp/src/main/webapp/includes/jira/dialog/userhover.js
@@ -7,9 +7,9 @@
  *      dialog popups.
  *
  * @param {HTMLElement} context (optional)
- *   -- The scope in which to look for "a.user-hover" elements
+ *   -- The scope in which to look for ".user-hover" elements
  */
-jQuery(document).delegate(".user-hover", {
+jQuery(document).delegate(".user-hover[rel]", {
     "mousemove": function() {
         JIRA.userhover.show(this);
     },

• The javascript tries to pick up the "rel" attribute from the element that specifies the "user-hover" class.
• The trouble starts in actionProfileLink.vm, which has three cases:
  1. We have a user: creates an anchor with class="user-hover user-avatar" and rel="username" with the escaped username as the content
  2. We have a username, but no user (user was deleted): creates a span with class="user-hover user-avatar" and no rel attribute with the escaped username as the content
  3. We have nothing (anonymous activity): creates a span with class="user-hover user-avatar" and no rel attribute with the translation for Anonymous as the content
• userhover.js always expects to find a rel attribute set for anything with the user-hover class. It appends the URL-escaped form of the username as a parameter to ViewUserHover.jspa
• viewuserhover.jsp is just working with what it was given, which is the literal string "null" as the username

What I think should happen:

1. Either the deleted user (Case 2) should not have the user-hover class, or rel should be set to the username.
2. Either the anonymous user (Case 3) should not have the user-hover class, or actionProfileLink and userhover.js need to sort out how to communicate this so that ViewUserHover.jspa is provided with a blank username instead of the literal string "null". Either setting rel to an empty value or having userhover.js tolerate a missing rel attribute would work.

This would be a combination of:

• Javascript functionality for the userhover
• Either:
  • A REST endpoint for retrieving a user's details, or
  • Something being output to the page on pageload with the user's details prepopulated in it.

In any case, the fix will be a combination of updating the javascript to recognise null/deleted users and output a special message.

I would agree with what edalgliesh has suggested. mlassau thoughts?

Can I infer from JRA-22817 that the desired behaviour is to not show this dialog for non-existent users at all?

Existing issue so move to JAC?