[PATCH v2 2/6] merge-ort: allow rename detection to be disabled
- From
Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Mar 13, 2025, 02:46 UTC
- Message-ID
- <f401a8e09676c9c808792665c3ffadd9d2672485.1741834001.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1875.v2.git.1741834001.gitgitgadget@gmail.com>
From: Elijah Newren <newren@gmail.com>
When merge-ort was written, I did not at first allow rename detection to be disabled, because I suspected that most folks disabling rename detection were doing so solely for performance reasons. Since I put a lot of working into providing dramatic speedups for rename detection performance as used by the merge machinery, I wanted to know if there were still real world repositories where rename detection was problematic from a performance perspective. We have had years now to collect such information, and while we never received one, waiting longer with the option disabled seems unlikely to help surface such issues at this point. Also, there has been at least one request to allow rename detection to be disabled for behavioral rather than performance reasons (see the thread including https://lore.kernel.org/git/CABPp-BG-Nx6SCxxkGXn_Fwd2wseifMFND8eddvWxiZVZk0zRaA@mail.gmail.com/ ), so let's start heeding the config and command line settings.
Signed-off-by: Elijah Newren <newren@gmail.com> --- Documentation/merge-strategies.adoc | 12 ++++++------ merge-ort.c | 5 +++++ t/t4301-merge-tree-write-tree.sh | 6 ++++++ 3 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/Documentation/merge-strategies.adoc b/Documentation/merge-strategies.adoc index 93822ebc4e8..59f5ae36ccb 100644 --- a/Documentation/merge-strategies.adoc +++ b/Documentation/merge-strategies.adoc @@ -82,6 +82,11 @@ find-renames[=<n>];; rename-threshold=<n>;; Deprecated synonym for `find-renames=<n>`. +no-renames;; + Turn off rename detection. This overrides the `merge.renames` + configuration variable. + See also linkgit:git-diff[1] `--no-renames`. + subtree[=<path>];; This option is a more advanced form of 'subtree' strategy, where the strategy makes a guess on how two trees must be shifted to @@ -107,7 +112,7 @@ For a path that is a submodule, the same caution as 'ort' applies to this strategy. + The 'recursive' strategy takes the same options as 'ort'. However, -there are three additional options that 'ort' ignores (not documented +there are two additional options that 'ort' ignores (not documented above) that are potentially useful with the 'recursive' strategy: patience;; @@ -121,11 +126,6 @@ diff-algorithm=[patience|minimal|histogram|myers];; specifically uses `diff-algorithm=histogram`, while `recursive` defaults to the `diff.algorithm` config setting. -no-renames;; - Turn off rename detection. This overrides the `merge.renames` - configuration variable. - See also linkgit:git-diff[1] `--no-renames`. - resolve:: This can only resolve two heads (i.e. the current branch and another branch you pulled from) using a 3-way merge diff --git a/merge-ort.c b/merge-ort.c index b4ff24403a1..1d3b690224e 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -3448,6 +3448,11 @@ static int detect_and_process_renames(struct merge_options *opt) if (!possible_renames(renames)) goto cleanup; + if (!opt->detect_renames) { + renames->redo_after_renames = 0; + renames->cached_pairs_valid_side = 0; + goto cleanup; + } trace2_region_enter("merge", "regular renames", opt->repo); detection_run |= detect_regular_renames(opt, MERGE_SIDE1); diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh index eea19907b55..44f7d077593 100755 --- a/t/t4301-merge-tree-write-tree.sh +++ b/t/t4301-merge-tree-write-tree.sh @@ -73,6 +73,12 @@ test_expect_success 'Clean merge' ' test_cmp expect actual ' +# Repeat the previous test, but turn off rename detection +test_expect_success 'Failed merge without rename detection' ' + test_must_fail git -c diff.renames=false merge-tree --write-tree side1 side3 >out && + grep "CONFLICT (modify/delete): numbers deleted" out +' + test_expect_success 'Content merge and a few conflicts' ' git checkout side1^0 && test_must_fail git merge side2 &&
-- gitgitgadget