It's missing an update to the topics table with their new date/time/subject etc of the new latest post in the topic.

Both with merged topics and merged posts.

I just ran into this bug when trying to merge a post and its replies to another topic.

In threaded mode, the thread structure looks fine but in flat mode, the order is out of whack.

blaaskaak, do you have a manual fix for this?

No...

When you merge topics, in flatmode the order that the topic is shown is in the original posting order.

It's not that topic A is appended to topic B, they are merged, as in mixed together if both topics ran simultaniously.

The bug repored is about when you merge topic A to topic B, topic B's last post date/time/subject is not updated to reflect the latest topic in that topic.

Hmm, maybe I'm reporting a different bug then?

Here's what happened with me. I had two topics, say topic A and topic B.

Topic A had 6 replies:

A.0, A.1, A.2, A.3, A.4, A.5

Topic B had 0 replies (i.e. just the single post):

B.0

I merged Topic A to Topic B, and when viewing the end result in Flat Mode, I got the following:

A.0, B.0, A.1, A.2, A.3, A.4, A.5

What I expected to see was:

B.0, A.0, A.1, A.2, A.3, A.4, A.5

Looking in showflat.php, I notice that the main query just sorts by the Post ID, which is effectively sorting chronologically:



But this doesn't guarantee that the main parent post of a topic gets displayed first! As shown in my example above.

So I changed it such that the main parent post will always appear first, and then the remaining posts are in chronological order:



So, I still think I have found a bug in that the parent post (where POST_IS_TOPIC=1) isn't gauranteed to display first in Flat Mode.

Don't know if you can consider it a bug. Merging is merging, 2 seperate topics become one. The only difference in merging topic A to B or B to A is the one that might get "This topic has merged" topic.

In flatmode, the normal vieworder is chronologically, so I think it works as designed.

What could be doable is an extra option called "Append topics", where a topic is appended to the target topic.

In normal day life, this isn't so much of a bother to use. We mainly use merge when somebody opens a new topic when there is already an older one about the same subject. You just merge them, and no troubles there (well, except bug #1 in this topic).

Consider this then:

• You're viewing the post list in the Changelog forum
• You click on the topic titled "Current Changelog" started by Rick
• The next thing you see is Rick's post, as expected. But it appears half-way down the page.
• When you scroll up you see there are other posts before Rick's.

Bug or not a bug?

Who started the topic?

p.s. assume there are no new posts in the thread, and the posts appearing before Rick were not posted by him.

My situation

Topic 1
Topic 2
Topic 3
Topic 4
Topic 5
Topic 7
Topic 8
Topic 9

Merge topic 2 into topic 8... result:

Topic 1
Topic 3
Topic 4
Topic 5
Topic 7
Topic 8
Topic 9

Topic 8 should be on the spot where topic 2 used to be.

Yeah, what I think we're going to have to do is actually create an entirely new topic out of the merged topics. Right now we're just changing the topic id of the posts, and it's leading to some inconsistencies with how the merged topics are displayed.

Rick, I actually think I might have fixed this in 7.3. We just needed to run rebuild_topic_data($topic_id) for the topic that was merged into.

Ah cool, thanks Ian