This series depends on en/merge-ort-2 (it does NOT depend on en/merge-ort-3 and can thus be reviewed/merged independently of it). This short series adds handling of recursive merges (merging of multiple merge-bases to create a virtual merge base) to merge-ort. With this short series the number of test failures under GIT_TEST_MERGE_ALGORITHM=ort drops by 801 (from 1448 to 647). Changes since v1 (based on review comments from Junio): * add documentation on why we reverse the commit_list of merge bases * modify the special override for allowing opt->ancestor to be set before merge_incore_recursive() and document its rationale Elijah Newren (3): merge-ort: copy a few small helper functions from merge-recursive.c merge-ort: make clear_internal_opts() aware of partial clearing merge-ort: implement merge_incore_recursive() merge-ort.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++--- merge-ort.h | 10 ++++ 2 files changed, 152 insertions(+), 7 deletions(-) base-commit: c5a6f65527aa3b6f5d7cf25437a88d8727ab0646 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-814%2Fnewren%2Fort-recursive-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-814/newren/ort-recursive-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/814 Range-diff vs v1: 1: 0b455bd6fe7 = 1: 0b455bd6fe7 merge-ort: copy a few small helper functions from merge-recursive.c 2: fc26c1a11db = 2: fc26c1a11db merge-ort: make clear_internal_opts() aware of partial clearing 3: 82a773d8972 ! 3: d8f79450a40 merge-ort: implement merge_incore_recursive() @@ merge-ort.c: static void merge_ort_nonrecursive_internal(struct merge_options *o + + if (!merge_bases) { + merge_bases = get_merge_bases(h1, h2); ++ /* See merge-ort.h:merge_incore_recursive() declaration NOTE */ + merge_bases = reverse_commit_list(merge_bases); + } + @@ merge-ort.c: void merge_incore_recursive(struct merge_options *opt, - (void)reverse_commit_list; - (void)make_virtual_commit; - die("Not yet implemented"); -+ assert(opt->ancestor == NULL || -+ !strcmp(opt->ancestor, "constructed merge base")); ++ /* ++ * merge_incore_nonrecursive() exists for cases where we always ++ * know there is a well-defined single merge base. However, ++ * despite a similar structure, merge-recursive.c noted that some ++ * callers preferred to call the recursive logic anyway and still ++ * set a special name for opt->ancestor that would appear in ++ * merge.conflictStyle=diff3 output. ++ * ++ * git-am was one such example (it wanted to set opt->ancestor to ++ * "constructed merge base", since it created a fake merge base); ++ * it called the recursive merge logic through a special ++ * merge_recursive_generic() wrapper. ++ * ++ * Allow the same kind of special case here. ++ */ ++ int num_merge_bases_is_1 = (merge_bases && !merge_bases->next); ++ assert(opt->ancestor == NULL || num_merge_bases_is_1); + + merge_start(opt, result); + merge_ort_internal(opt, merge_bases, side1, side2, result); } + + ## merge-ort.h ## +@@ merge-ort.h: struct merge_result { + /* + * rename-detecting three-way merge with recursive ancestor consolidation. + * working tree and index are untouched. ++ * ++ * merge_bases will be consumed (emptied) so make a copy if you need it. ++ * ++ * NOTE: empirically, the recursive algorithm will perform better if you ++ * pass the merge_bases in the order of oldest commit to the ++ * newest[1][2]. ++ * ++ * [1] https://lore.kernel.org/git/nycvar.QRO.7.76.6.1907252055500.21907@xxxxxxxxxxxxxxxxx/ ++ * [2] commit 8918b0c9c2 ("merge-recur: try to merge older merge bases ++ * first", 2006-08-09) + */ + void merge_incore_recursive(struct merge_options *opt, + struct commit_list *merge_bases, -- gitgitgadget
