Note I reported the original issue at https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)/Archive_207#Vector_2022_table_of_contents:_bolded_heading_differing_from_current_scroll_position . As I identified in that posting, the bolded heading is not random, but one within the collapsed section of text.

Another example: compare https://en.wikipedia.org/w/index.php?title=Wikipedia:Arbitration/Requests/Clarification_and_Amendment&oldid=1167627265 with https://en.wikipedia.org/w/index.php?title=Wikipedia:Arbitration/Requests/Clarification_and_Amendment&oldid=1167874333

In T120794#8277692, @PerfektesChaos wrote:

In T120794#8277562, @Winston_Sung wrote:

Also, would we like to support localized #REDIRECT or keep it in English?

English is sufficient, since the audience are Lua programmers rather than encyclopedic authors. Lua is English.

My major concern is that someone encounters the module link and asks which bloody fool wrote a module of one silly line.

I don't think the comparison to TemplateStyles regarding security risk is fully apt. I think the worst that can happen with style rules is that the real destination of a link can be obscured. This can be a problem but the damage is constrained to things that can happen when you visit some arbitrary URL. Malicious Javascript, on the other hand, runs in the context of the client and can do anything the Javascript API allows.

Here is another example of a diff that hangs, also with a error message in the console:
jQuery.Deferred exception: Cannot read property 'type' of undefined TypeError: Cannot read property 'type' of undefined

I tried creating a minimal test case, but haven't succeeded so far. These two diffs don't hang:

Here's a slightly different example, where an editor added an {{anchor}} template within a description list and the visual diff output hangs:

As an interim step, can the exception be caught and some recovery action be taken?

I created some test cases to try to isolate the problem.

Note although I did not keep track of other instances, I have seen other cases where mis-nested markup, similar to that in the example, have resulted in hanging. After identifying this commonality, I started the thread linked above.

Is there any update on the status of this task? This would enable renaming a deployed module seamlessly, without having to resort to a copy-and-paste move to the new module name, followed by redirecting the old module to the new one.

In T218511#5107077, @IKhitron wrote:

In T218511#5106768, @TheDJ wrote:

@isaacl mentions: "I'm still having the opposite issue that I mentioned before: diffs being marked as read even though they weren't, but on occasion I also see the issue that everyone else is complaining about regarding diffs that have been read"

Maybe I do know why. Does this still happen in safemode?