| Message ID | pull.1194.git.git.1642212566346.gitgitgadget@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | merge-ort: avoid assuming all renames detected | expand |
"Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes: > From: Elijah Newren <newren@gmail.com> > > 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@ttaylorr.com> > Signed-off-by: Elijah Newren <newren@gmail.com> > --- Thanks. Will fork from maint-2.33 and park on 'seen' for now.
"Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes: > diff --git a/merge-ort.c b/merge-ort.c > index c3197970219..143d274f117 100644 > --- a/merge-ort.c > +++ b/merge-ort.c > @@ -3060,6 +3060,10 @@ static int detect_and_process_renames(struct merge_options *opt, > trace2_region_enter("merge", "regular renames", opt->repo); > detection_run |= detect_regular_renames(opt, MERGE_SIDE1); > detection_run |= detect_regular_renames(opt, MERGE_SIDE2); > + if (renames->needed_limit != 0) { Don't compare with NULL or 0, i.e. if (renames->needed_limit) { > + renames->cached_pairs_valid_side = 0; > + renames->redo_after_renames = 0; > + } > if (renames->redo_after_renames && detection_run) { > int i, side; > struct diff_filepair *p;
diff --git a/merge-ort.c b/merge-ort.c index c3197970219..143d274f117 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -3060,6 +3060,10 @@ static int detect_and_process_renames(struct merge_options *opt, trace2_region_enter("merge", "regular renames", opt->repo); detection_run |= detect_regular_renames(opt, MERGE_SIDE1); detection_run |= detect_regular_renames(opt, MERGE_SIDE2); + if (renames->needed_limit != 0) { + renames->cached_pairs_valid_side = 0; + renames->redo_after_renames = 0; + } if (renames->redo_after_renames && detection_run) { int i, side; struct diff_filepair *p; diff --git a/t/t6429-merge-sequence-rename-caching.sh b/t/t6429-merge-sequence-rename-caching.sh index 035edc40b1e..f2bc8a7d2a2 100755 --- a/t/t6429-merge-sequence-rename-caching.sh +++ b/t/t6429-merge-sequence-rename-caching.sh @@ -697,4 +697,71 @@ test_expect_success 'caching renames only on upstream side, part 2' ' ) ' +# +# The following testcase just creates two simple renames (slightly modified +# on both sides but without conflicting changes), and a directory full of +# files that are otherwise uninteresting. The setup is as follows: +# +# base: unrelated/<BUNCH OF FILES> +# numbers +# values +# upstream: modify: numbers +# modify: values +# topic: add: unrelated/foo +# modify: numbers +# modify: values +# rename: numbers -> sequence +# rename: values -> progression +# +# This is a trivial rename case, but we're curious what happens with a very +# low renameLimit interacting with the restart optimization trying to notice +# that unrelated/ looks like a trivial merge candidate. +# +test_expect_success 'avoid assuming we detected renames' ' + git init redo-weirdness && + ( + cd redo-weirdness && + + mkdir unrelated && + for i in $(test_seq 1 10) + do + >unrelated/$i + done && + test_seq 2 10 >numbers && + test_seq 12 20 >values && + git add numbers values unrelated/ && + git commit -m orig && + + git branch upstream && + git branch topic && + + git switch upstream && + test_seq 1 10 >numbers && + test_seq 11 20 >values && + git add numbers && + git commit -m "Some tweaks" && + + git switch topic && + + >unrelated/foo && + test_seq 2 12 >numbers && + test_seq 12 22 >values && + git add numbers values unrelated/ && + git mv numbers sequence && + git mv values progression && + git commit -m A && + + # + # Actual testing + # + + git switch --detach topic^0 && + + test_must_fail git -c merge.renameLimit=1 rebase upstream && + + git ls-files -u >actual && + ! test_file_is_empty actual + ) +' + test_done