"Elijah Newren via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> From: Elijah Newren <newren@xxxxxxxxx>
>
> In commit 8b09a900a1 ("merge-ort: restart merge with cached renames to
> reduce process entry cost", 2021-07-16), we noted that in the merge-ort
> steps of
> collect_merge_info()
> detect_and_process_renames()
> process_entries()
> that process_entries() was expensive, and we could often make it cheaper
> by changing this to
> collect_merge_info()
> detect_and_process_renames()
> <cache all the renames, and restart>
> collect_merge_info()
> detect_and_process_renames()
> process_entries()
> because the second collect_merge_info() would be cheaper (we could avoid
> traversing into some directories), the second
> detect_and_process_renames() would be free since we had already detected
> all renames, and then process_entries() has far fewer entries to handle.
>
> However, this was built on the assumption that the first
> detect_and_process_renames() actually detected all potential renames.
> If someone has merge.renameLimit set to some small value, that
> assumption is violated which manifests later with the following message:
>
> $ git -c merge.renameLimit=1 rebase upstream
> ...
> git: merge-ort.c:546: clear_or_reinit_internal_opts: Assertion
> `renames->cached_pairs_valid_side == 0' failed.
>
> Turn off this cache-renames-and-restart whenever we cannot detect all
> renames, and add a testcase that would have caught this problem.
>
> Reported-by: Taylor Blau <me@xxxxxxxxxxxx>
> Signed-off-by: Elijah Newren <newren@xxxxxxxxx>
> ---
Thanks. Will fork from maint-2.33 and park on 'seen' for now.
