And as I showed there, and as one of the posts is eventually marked the solution … the merge function always did the automerge thing (using $MERGEPROG) and only after that would use DIFFPROG to show you the old file and the automerged one. The m has always included the automerge - it is its function.
Some logic around how it did the automerge changed slightly … but if you wanted to avoid some sort of automerge … then you should never have been using m.
The suggestion is, was, and will continue to be - use view.
Then compare and ‘merge’ by hand as needed.
This may not, indeed in my experience rarely does, produce an ‘identical file’.
(You have an edited file, which is why you have the pacnew, for a reason usually. Custom options, etc.)
Back to the issue at hand …
Does not strike me as inherently incorrect.
This is likely what my actions and output would look like most of the time.
It all hinges of course on what edits were made during ‘view’.
But if they were correct - this sequence of events is entirely normal and acceptable practice.