From 72b3091040f8d2784225527ebecfc3c2a56fe196 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:44 +0000 Subject: [PATCH 01/13] merge-ort: use STABLE_QSORT instead of QSORT where required rename/rename conflict handling depends on the fact that if both sides renamed the same path, that the one on the MERGE_SIDE1 will appear first in the combined diff_queue_struct passed to process_renames(). Since we add all pairs from MERGE_SIDE1 to combined first, and then all pairs from MERGE_SIDE2, and then sort based on filename, this will only be true if the sort used is stable. This was found due to the fact that Mac, unlike Linux, apparently has a system-defined qsort that is not stable. While we are at it, review the other callers of QSORT and add comments about why they can remain as calls to QSORT instead of being modified to call STABLE_QSORT. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/merge-ort.c b/merge-ort.c index 7f5750ce6ab0c9..34a91c43573752 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -2405,7 +2405,7 @@ static int detect_and_process_renames(struct merge_options *opt, clean &= collect_renames(opt, &combined, MERGE_SIDE2, &renames->dir_renames[1], &renames->dir_renames[2]); - QSORT(combined.queue, combined.nr, compare_pairs); + STABLE_QSORT(combined.queue, combined.nr, compare_pairs); trace2_region_leave("merge", "directory renames", opt->repo); trace2_region_enter("merge", "process renames", opt->repo); @@ -2550,6 +2550,7 @@ static void write_tree(struct object_id *result_oid, */ relevant_entries.items = versions->items + offset; relevant_entries.nr = versions->nr - offset; + /* No need for STABLE_QSORT -- filenames must be unique */ QSORT(relevant_entries.items, relevant_entries.nr, tree_entry_order); /* Pre-allocate some space in buf */ @@ -3325,6 +3326,11 @@ static int record_conflicted_index_entries(struct merge_options *opt, * entries we added to the end into their right locations. */ remove_marked_cache_entries(index, 1); + /* + * No need for STABLE_QSORT -- cmp_cache_name_compare sorts primarily + * on filename and secondarily on stage, and (name, stage #) are a + * unique tuple. + */ QSORT(index->cache, index->cache_nr, cmp_cache_name_compare); return errs; From ea305a68fd7427f84f90709e598624341f5627c8 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:45 +0000 Subject: [PATCH 02/13] merge-ort: add a special minimal index just for renormalization renormalize_buffer() requires an index_state, which is something that merge-ort does not operate with. However, all the renormalization code needs is an index with a .gitattributes file...plus a little bit of setup. Create such an index, along with the deallocation and attr_direction handling. A subsequent commit will add a function to finish the initialization of this index. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/merge-ort.c b/merge-ort.c index 34a91c43573752..3c606fa7e4b3d7 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -18,6 +18,7 @@ #include "merge-ort.h" #include "alloc.h" +#include "attr.h" #include "blob.h" #include "cache-tree.h" #include "commit.h" @@ -220,6 +221,16 @@ struct merge_options_internal { */ struct rename_info renames; + /* + * attr_index: hacky minimal index used for renormalization + * + * renormalization code _requires_ an index, though it only needs to + * find a .gitattributes file within the index. So, when + * renormalization is important, we create a special index with just + * that one file. + */ + struct index_state attr_index; + /* * current_dir_name, toplevel_dir: temporary vars * @@ -399,6 +410,9 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti, string_list_clear(&opti->paths_to_free, 0); opti->paths_to_free.strdup_strings = 0; + if (opti->attr_index.cache_nr) + discard_index(&opti->attr_index); + /* Free memory used by various renames maps */ for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) { strintmap_func(&renames->dirs_removed[i]); @@ -3407,6 +3421,8 @@ void merge_finalize(struct merge_options *opt, { struct merge_options_internal *opti = result->priv; + if (opt->renormalize) + git_attr_set_direction(GIT_ATTR_CHECKIN); assert(opt->priv == NULL); clear_or_reinit_internal_opts(opti, 0); @@ -3482,6 +3498,10 @@ static void merge_start(struct merge_options *opt, struct merge_result *result) /* Default to histogram diff. Actually, just hardcode it...for now. */ opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF); + /* Handle attr direction stuff for renormalization */ + if (opt->renormalize) + git_attr_set_direction(GIT_ATTR_CHECKOUT); + /* Initialization of opt->priv, our internal merge data */ trace2_region_enter("merge", "allocate/init", opt->repo); if (opt->priv) { From 1218b3ab86ddeea7c10ea3da0a1cdd5c026d1252 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:46 +0000 Subject: [PATCH 03/13] merge-ort: have ll_merge() use a special attr_index for renormalization ll_merge() needs an index when renormalization is requested. Create one specifically for just this purpose with just the one needed entry. This fixes t6418.4 and t6418.5 under GIT_TEST_MERGE_ALGORITHM=ort. NOTE 1: Even if the user has a working copy or a real index (which is not a given as merge-ort can be used in bare repositories), we explicitly ignore any .gitattributes file from either of these locations. merge-ort can be used to merge two branches that are unrelated to HEAD, so .gitattributes from the working copy and current index should not be considered relevant. NOTE 2: Since we are in the middle of merging, there is a risk that .gitattributes itself is conflicted...leaving us with an ill-defined situation about how to perform the rest of the merge. It could be that the .gitattributes file does not even exist on one of the sides of the merge, or that it has been modified on both sides. If it's been modified on both sides, it's possible that it could itself be merged cleanly, though it's also possible that it only merges cleanly if you use the right version of the .gitattributes file to drive the merge. It gets kind of complicated. The only test we ever had that attempted to test behavior in this area was seemingly unaware of the undefined behavior, but knew the test wouldn't work for lack of attribute handling support, marked it as test_expect_failure from the beginning, but managed to fail for several reasons unrelated to attribute handling. See commit 6f6e7cfb52 ("t6038: remove problematic test", 2020-08-03) for details. So there are probably various ways to improve what initialize_attr_index() picks in the case of a conflicted .gitattributes but for now I just implemented something simple -- look for whatever .gitattributes file we can find in any of the higher order stages and use it. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 2 deletions(-) diff --git a/merge-ort.c b/merge-ort.c index 3c606fa7e4b3d7..cdc1e2fe7a24b0 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -410,7 +410,7 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti, string_list_clear(&opti->paths_to_free, 0); opti->paths_to_free.strdup_strings = 0; - if (opti->attr_index.cache_nr) + if (opti->attr_index.cache_nr) /* true iff opt->renormalize */ discard_index(&opti->attr_index); /* Free memory used by various renames maps */ @@ -1201,6 +1201,63 @@ static int merge_submodule(struct merge_options *opt, return 0; } +static void initialize_attr_index(struct merge_options *opt) +{ + /* + * The renormalize_buffer() functions require attributes, and + * annoyingly those can only be read from the working tree or from + * an index_state. merge-ort doesn't have an index_state, so we + * generate a fake one containing only attribute information. + */ + struct merged_info *mi; + struct index_state *attr_index = &opt->priv->attr_index; + struct cache_entry *ce; + + attr_index->initialized = 1; + + if (!opt->renormalize) + return; + + mi = strmap_get(&opt->priv->paths, GITATTRIBUTES_FILE); + if (!mi) + return; + + if (mi->clean) { + int len = strlen(GITATTRIBUTES_FILE); + ce = make_empty_cache_entry(attr_index, len); + ce->ce_mode = create_ce_mode(mi->result.mode); + ce->ce_flags = create_ce_flags(0); + ce->ce_namelen = len; + oidcpy(&ce->oid, &mi->result.oid); + memcpy(ce->name, GITATTRIBUTES_FILE, len); + add_index_entry(attr_index, ce, + ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); + get_stream_filter(attr_index, GITATTRIBUTES_FILE, &ce->oid); + } else { + int stage, len; + struct conflict_info *ci; + + ASSIGN_AND_VERIFY_CI(ci, mi); + for (stage = 0; stage < 3; stage++) { + unsigned stage_mask = (1 << stage); + + if (!(ci->filemask & stage_mask)) + continue; + len = strlen(GITATTRIBUTES_FILE); + ce = make_empty_cache_entry(attr_index, len); + ce->ce_mode = create_ce_mode(ci->stages[stage].mode); + ce->ce_flags = create_ce_flags(stage); + ce->ce_namelen = len; + oidcpy(&ce->oid, &ci->stages[stage].oid); + memcpy(ce->name, GITATTRIBUTES_FILE, len); + add_index_entry(attr_index, ce, + ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE); + get_stream_filter(attr_index, GITATTRIBUTES_FILE, + &ce->oid); + } + } +} + static int merge_3way(struct merge_options *opt, const char *path, const struct object_id *o, @@ -1215,6 +1272,9 @@ static int merge_3way(struct merge_options *opt, char *base, *name1, *name2; int merge_status; + if (!opt->priv->attr_index.initialized) + initialize_attr_index(opt); + ll_opts.renormalize = opt->renormalize; ll_opts.extra_marker_size = extra_marker_size; ll_opts.xdl_opts = opt->xdl_opts; @@ -1253,7 +1313,7 @@ static int merge_3way(struct merge_options *opt, merge_status = ll_merge(result_buf, path, &orig, base, &src1, name1, &src2, name2, - opt->repo->index, &ll_opts); + &opt->priv->attr_index, &ll_opts); free(base); free(name1); From 3860220bfa594a56daa801aaedbdf8ac75b62bb6 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:47 +0000 Subject: [PATCH 04/13] merge-ort: let renormalization change modify/delete into clean delete When we have a modify/delete conflict, but the only change to the modification is e.g. change of line endings, then if renormalization is requested then we should be able to recognize such a case as a not-modified/delete and resolve the conflict automatically. This fixes t6418.10 under GIT_TEST_MERGE_ALGORITHM=ort. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 2 deletions(-) diff --git a/merge-ort.c b/merge-ort.c index cdc1e2fe7a24b0..c7083e3769aa56 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -2549,6 +2549,61 @@ static int string_list_df_name_compare(const char *one, const char *two) return onelen - twolen; } +static int read_oid_strbuf(struct merge_options *opt, + const struct object_id *oid, + struct strbuf *dst) +{ + void *buf; + enum object_type type; + unsigned long size; + buf = read_object_file(oid, &type, &size); + if (!buf) + return err(opt, _("cannot read object %s"), oid_to_hex(oid)); + if (type != OBJ_BLOB) { + free(buf); + return err(opt, _("object %s is not a blob"), oid_to_hex(oid)); + } + strbuf_attach(dst, buf, size, size + 1); + return 0; +} + +static int blob_unchanged(struct merge_options *opt, + const struct version_info *base, + const struct version_info *side, + const char *path) +{ + struct strbuf basebuf = STRBUF_INIT; + struct strbuf sidebuf = STRBUF_INIT; + int ret = 0; /* assume changed for safety */ + const struct index_state *idx = &opt->priv->attr_index; + + if (!idx->initialized) + initialize_attr_index(opt); + + if (base->mode != side->mode) + return 0; + if (oideq(&base->oid, &side->oid)) + return 1; + + if (read_oid_strbuf(opt, &base->oid, &basebuf) || + read_oid_strbuf(opt, &side->oid, &sidebuf)) + goto error_return; + /* + * Note: binary | is used so that both renormalizations are + * performed. Comparison can be skipped if both files are + * unchanged since their sha1s have already been compared. + */ + if (renormalize_buffer(idx, path, basebuf.buf, basebuf.len, &basebuf) | + renormalize_buffer(idx, path, sidebuf.buf, sidebuf.len, &sidebuf)) + ret = (basebuf.len == sidebuf.len && + !memcmp(basebuf.buf, sidebuf.buf, basebuf.len)); + +error_return: + strbuf_release(&basebuf); + strbuf_release(&sidebuf); + return ret; +} + struct directory_versions { /* * versions: list of (basename -> version_info) @@ -3136,8 +3191,13 @@ static void process_entry(struct merge_options *opt, modify_branch = (side == 1) ? opt->branch1 : opt->branch2; delete_branch = (side == 1) ? opt->branch2 : opt->branch1; - if (ci->path_conflict && - oideq(&ci->stages[0].oid, &ci->stages[side].oid)) { + if (opt->renormalize && + blob_unchanged(opt, &ci->stages[0], &ci->stages[side], + path)) { + ci->merged.is_null = 1; + ci->merged.clean = 1; + } else if (ci->path_conflict && + oideq(&ci->stages[0].oid, &ci->stages[side].oid)) { /* * This came from a rename/delete; no action to take, * but avoid printing "modify/delete" conflict notice From 3639dfb3a8ea6935a7863fcbcc1c7a6c9104980e Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:48 +0000 Subject: [PATCH 05/13] merge-ort: support subtree shifting merge-recursive has some simple code to support subtree shifting; copy it over to merge-ort. This fixes t6409.12 under GIT_TEST_MERGE_ALGORITHM=ort. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/merge-ort.c b/merge-ort.c index c7083e3769aa56..c4fe234d897216 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -3551,6 +3551,23 @@ void merge_finalize(struct merge_options *opt, /*** Function Grouping: helper functions for merge_incore_*() ***/ +static struct tree *shift_tree_object(struct repository *repo, + struct tree *one, struct tree *two, + const char *subtree_shift) +{ + struct object_id shifted; + + if (!*subtree_shift) { + shift_tree(repo, &one->object.oid, &two->object.oid, &shifted, 0); + } else { + shift_tree_by(repo, &one->object.oid, &two->object.oid, &shifted, + subtree_shift); + } + if (oideq(&two->object.oid, &shifted)) + return two; + return lookup_tree(repo, &shifted); +} + static inline void set_commit_tree(struct commit *c, struct tree *t) { c->maybe_tree = t; @@ -3680,6 +3697,13 @@ static void merge_ort_nonrecursive_internal(struct merge_options *opt, { struct object_id working_tree_oid; + if (opt->subtree_shift) { + side2 = shift_tree_object(opt->repo, side1, side2, + opt->subtree_shift); + merge_base = shift_tree_object(opt->repo, side1, merge_base, + opt->subtree_shift); + } + trace2_region_enter("merge", "collect_merge_info", opt->repo); if (collect_merge_info(opt, merge_base, side1, side2) != 0) { /* From 8ddc20b8969120329a9369e19816aa9088c9550e Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:49 +0000 Subject: [PATCH 06/13] t6428: new test for SKIP_WORKTREE handling and conflicts If there is a conflict during a merge for a SKIP_WORKTREE entry, we expect that file to be written to the working copy and have the SKIP_WORKTREE bit cleared in the index. If the user had manually created a file in the working tree despite SKIP_WORKTREE being set, we do not want to clobber their changes to that file, but want to move it out of the way. Add tests that check for these behaviors. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t6428-merge-conflicts-sparse.sh | 158 ++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100755 t/t6428-merge-conflicts-sparse.sh diff --git a/t/t6428-merge-conflicts-sparse.sh b/t/t6428-merge-conflicts-sparse.sh new file mode 100755 index 00000000000000..1bb52ff6f38cb7 --- /dev/null +++ b/t/t6428-merge-conflicts-sparse.sh @@ -0,0 +1,158 @@ +#!/bin/sh + +test_description="merge cases" + +# The setup for all of them, pictorially, is: +# +# A +# o +# / \ +# O o ? +# \ / +# o +# B +# +# To help make it easier to follow the flow of tests, they have been +# divided into sections and each test will start with a quick explanation +# of what commits O, A, and B contain. +# +# Notation: +# z/{b,c} means files z/b and z/c both exist +# x/d_1 means file x/d exists with content d1. (Purpose of the +# underscore notation is to differentiate different +# files that might be renamed into each other's paths.) + +. ./test-lib.sh +. "$TEST_DIRECTORY"/lib-merge.sh + + +# Testcase basic, conflicting changes in 'numerals' + +test_setup_numerals () { + test_create_repo numerals_$1 && + ( + cd numerals_$1 && + + >README && + test_write_lines I II III >numerals && + git add README numerals && + test_tick && + git commit -m "O" && + + git branch O && + git branch A && + git branch B && + + git checkout A && + test_write_lines I II III IIII >numerals && + git add numerals && + test_tick && + git commit -m "A" && + + git checkout B && + test_write_lines I II III IV >numerals && + git add numerals && + test_tick && + git commit -m "B" && + + cat <<-EOF >expected-index && + H README + M numerals + M numerals + M numerals + EOF + + cat <<-EOF >expected-merge + I + II + III + <<<<<<< HEAD + IIII + ======= + IV + >>>>>>> B^0 + EOF + + ) +} + +test_expect_merge_algorithm success failure 'conflicting entries written to worktree even if sparse' ' + test_setup_numerals plain && + ( + cd numerals_plain && + + git checkout A^0 && + + test_path_is_file README && + test_path_is_file numerals && + + git sparse-checkout init && + git sparse-checkout set README && + + test_path_is_file README && + test_path_is_missing numerals && + + test_must_fail git merge -s recursive B^0 && + + git ls-files -t >index_files && + test_cmp expected-index index_files && + + test_path_is_file README && + test_path_is_file numerals && + + test_cmp expected-merge numerals && + + # 4 other files: + # * expected-merge + # * expected-index + # * index_files + # * others + git ls-files -o >others && + test_line_count = 4 others + ) +' + +test_expect_merge_algorithm failure failure 'present-despite-SKIP_WORKTREE handled reasonably' ' + test_setup_numerals in_the_way && + ( + cd numerals_in_the_way && + + git checkout A^0 && + + test_path_is_file README && + test_path_is_file numerals && + + git sparse-checkout init && + git sparse-checkout set README && + + test_path_is_file README && + test_path_is_missing numerals && + + echo foobar >numerals && + + test_must_fail git merge -s recursive B^0 && + + git ls-files -t >index_files && + test_cmp expected-index index_files && + + test_path_is_file README && + test_path_is_file numerals && + + test_cmp expected-merge numerals && + + # There should still be a file with "foobar" in it + grep foobar * && + + # 5 other files: + # * expected-merge + # * expected-index + # * index_files + # * others + # * whatever name was given to the numerals file that had + # "foobar" in it + git ls-files -o >others && + test_line_count = 5 others + ) +' + +test_done From 66b209b86ad3b79728d3f0f22e1bdef6b17a12c1 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:50 +0000 Subject: [PATCH 07/13] merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries When merge conflicts occur in paths removed by a sparse-checkout, we need to unsparsify those paths (clear the SKIP_WORKTREE bit), and write out the conflicted file to the working copy. In the very unlikely case that someone manually put a file into the working copy at the location of the SKIP_WORKTREE file, we need to avoid overwriting whatever edits they have made and move that file to a different location first. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 43 +++++++++++++++++++++---------- t/t6428-merge-conflicts-sparse.sh | 4 +-- 2 files changed, 32 insertions(+), 15 deletions(-) diff --git a/merge-ort.c b/merge-ort.c index c4fe234d897216..303e894142743e 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -3369,23 +3369,27 @@ static int checkout(struct merge_options *opt, return ret; } -static int record_conflicted_index_entries(struct merge_options *opt, - struct index_state *index, - struct strmap *paths, - struct strmap *conflicted) +static int record_conflicted_index_entries(struct merge_options *opt) { struct hashmap_iter iter; struct strmap_entry *e; + struct index_state *index = opt->repo->index; + struct checkout state = CHECKOUT_INIT; int errs = 0; int original_cache_nr; - if (strmap_empty(conflicted)) + if (strmap_empty(&opt->priv->conflicted)) return 0; + /* If any entries have skip_worktree set, we'll have to check 'em out */ + state.force = 1; + state.quiet = 1; + state.refresh_cache = 1; + state.istate = index; original_cache_nr = index->cache_nr; /* Put every entry from paths into plist, then sort */ - strmap_for_each_entry(conflicted, &iter, e) { + strmap_for_each_entry(&opt->priv->conflicted, &iter, e) { const char *path = e->key; struct conflict_info *ci = e->value; int pos; @@ -3426,9 +3430,23 @@ static int record_conflicted_index_entries(struct merge_options *opt, * the higher order stages. Thus, we need override * the CE_SKIP_WORKTREE bit and manually write those * files to the working disk here. - * - * TODO: Implement this CE_SKIP_WORKTREE fixup. */ + if (ce_skip_worktree(ce)) { + struct stat st; + + if (!lstat(path, &st)) { + char *new_name = unique_path(&opt->priv->paths, + path, + "cruft"); + + path_msg(opt, path, 1, + _("Note: %s not up to date and in way of checking out conflicted version; old copy renamed to %s"), + path, new_name); + errs |= rename(path, new_name); + free(new_name); + } + errs |= checkout_entry(ce, &state, NULL, NULL); + } /* * Mark this cache entry for removal and instead add @@ -3478,8 +3496,6 @@ void merge_switch_to_result(struct merge_options *opt, { assert(opt->priv == NULL); if (result->clean >= 0 && update_worktree_and_index) { - struct merge_options_internal *opti = result->priv; - trace2_region_enter("merge", "checkout", opt->repo); if (checkout(opt, head, result->tree)) { /* failure to function */ @@ -3489,13 +3505,14 @@ void merge_switch_to_result(struct merge_options *opt, trace2_region_leave("merge", "checkout", opt->repo); trace2_region_enter("merge", "record_conflicted", opt->repo); - if (record_conflicted_index_entries(opt, opt->repo->index, - &opti->paths, - &opti->conflicted)) { + opt->priv = result->priv; + if (record_conflicted_index_entries(opt)) { /* failure to function */ + opt->priv = NULL; result->clean = -1; return; } + opt->priv = NULL; trace2_region_leave("merge", "record_conflicted", opt->repo); } diff --git a/t/t6428-merge-conflicts-sparse.sh b/t/t6428-merge-conflicts-sparse.sh index 1bb52ff6f38cb7..7e8bf497f821da 100755 --- a/t/t6428-merge-conflicts-sparse.sh +++ b/t/t6428-merge-conflicts-sparse.sh @@ -76,7 +76,7 @@ test_setup_numerals () { ) } -test_expect_merge_algorithm success failure 'conflicting entries written to worktree even if sparse' ' +test_expect_success 'conflicting entries written to worktree even if sparse' ' test_setup_numerals plain && ( cd numerals_plain && @@ -112,7 +112,7 @@ test_expect_merge_algorithm success failure 'conflicting entries written to work ) ' -test_expect_merge_algorithm failure failure 'present-despite-SKIP_WORKTREE handled reasonably' ' +test_expect_merge_algorithm failure success 'present-despite-SKIP_WORKTREE handled reasonably' ' test_setup_numerals in_the_way && ( cd numerals_in_the_way && From aa2faac03ad646873ebac2b230581d1d26dd1b99 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:51 +0000 Subject: [PATCH 08/13] t: mark several submodule merging tests as fixed under merge-ort merge-ort handles submodules (and directory/file conflicts in general) differently than merge-recursive does; it basically puts all the special handling for different filetypes into one place in the codebase instead of needing special handling for different filetypes in many different code paths. This one code path in merge-ort could perhaps use some work still (there are still test_expect_failure cases in the testsuite), but it passes all the tests that merge-recursive does as well as 12 additional ones that merge-recursive fails. Mark those 12 tests as test_expect_success under merge-ort. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t3512-cherry-pick-submodule.sh | 7 +++++-- t/t3513-revert-submodule.sh | 5 ++++- t/t5572-pull-submodule.sh | 7 +++++-- t/t6437-submodule-merge.sh | 5 +++-- t/t6438-submodule-directory-file-conflicts.sh | 7 +++++-- 5 files changed, 22 insertions(+), 9 deletions(-) diff --git a/t/t3512-cherry-pick-submodule.sh b/t/t3512-cherry-pick-submodule.sh index 822f2d4bfbd5ad..c657840db33b6e 100755 --- a/t/t3512-cherry-pick-submodule.sh +++ b/t/t3512-cherry-pick-submodule.sh @@ -8,8 +8,11 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME . ./test-lib.sh . "$TEST_DIRECTORY"/lib-submodule-update.sh -KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 -KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +if test "$GIT_TEST_MERGE_ALGORITHM" != ort +then + KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 + KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +fi test_submodule_switch "cherry-pick" test_expect_success 'unrelated submodule/file conflict is ignored' ' diff --git a/t/t3513-revert-submodule.sh b/t/t3513-revert-submodule.sh index a759f12cbb1d6b..74cd96e582234f 100755 --- a/t/t3513-revert-submodule.sh +++ b/t/t3513-revert-submodule.sh @@ -30,7 +30,10 @@ git_revert () { git revert HEAD } -KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 +if test "$GIT_TEST_MERGE_ALGORITHM" != ort +then + KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 +fi test_submodule_switch_func "git_revert" test_done diff --git a/t/t5572-pull-submodule.sh b/t/t5572-pull-submodule.sh index 29537f4798ef85..4f92a116e1f0ec 100755 --- a/t/t5572-pull-submodule.sh +++ b/t/t5572-pull-submodule.sh @@ -42,8 +42,11 @@ git_pull_noff () { $2 git pull --no-ff } -KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 -KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +if test "$GIT_TEST_MERGE_ALGORITHM" != ort +then + KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 + KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +fi test_submodule_switch_func "git_pull_noff" test_expect_success 'pull --recurse-submodule setup' ' diff --git a/t/t6437-submodule-merge.sh b/t/t6437-submodule-merge.sh index 0f92bcf326c848..e5e89c2045e714 100755 --- a/t/t6437-submodule-merge.sh +++ b/t/t6437-submodule-merge.sh @@ -6,6 +6,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME . ./test-lib.sh +. "$TEST_DIRECTORY"/lib-merge.sh # # history @@ -328,7 +329,7 @@ test_expect_success 'setup file/submodule conflict' ' ) ' -test_expect_failure 'file/submodule conflict' ' +test_expect_merge_algorithm failure success 'file/submodule conflict' ' test_when_finished "git -C file-submodule reset --hard" && ( cd file-submodule && @@ -437,7 +438,7 @@ test_expect_failure 'directory/submodule conflict; keep submodule clean' ' ) ' -test_expect_failure !FAIL_PREREQS 'directory/submodule conflict; should not treat submodule files as untracked or in the way' ' +test_expect_merge_algorithm failure success !FAIL_PREREQS 'directory/submodule conflict; should not treat submodule files as untracked or in the way' ' test_when_finished "git -C directory-submodule/path reset --hard" && test_when_finished "git -C directory-submodule reset --hard" && ( diff --git a/t/t6438-submodule-directory-file-conflicts.sh b/t/t6438-submodule-directory-file-conflicts.sh index 04bf4be7d79224..8df67a0ef99d26 100755 --- a/t/t6438-submodule-directory-file-conflicts.sh +++ b/t/t6438-submodule-directory-file-conflicts.sh @@ -12,8 +12,11 @@ test_submodule_switch "merge --ff" test_submodule_switch "merge --ff-only" -KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 -KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +if test "$GIT_TEST_MERGE_ALGORITHM" != ort +then + KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1 + KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1 +fi test_submodule_switch "merge --no-ff" test_done From 5291828df8386ebeb01039d1403d9f845d2f6e20 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:52 +0000 Subject: [PATCH 09/13] merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict There are a variety of questions users might ask while resolving conflicts: * What changes have been made since the previous (first) parent? * What changes are staged? * What is still unstaged? (or what is still conflicted?) * What changes did I make to resolve conflicts so far? The first three of these have simple answers: * git diff HEAD * git diff --cached * git diff There was no way to answer the final question previously. Adding one is trivial in merge-ort, since it works by creating a tree representing what should be written to the working copy complete with conflict markers. Simply write that tree to .git/AUTO_MERGE, allowing users to answer the fourth question with * git diff AUTO_MERGE I avoided using a name like "MERGE_AUTO", because that would be merge-specific (much like MERGE_HEAD, REBASE_HEAD, REVERT_HEAD, CHERRY_PICK_HEAD) and I wanted a name that didn't change depending on which type of operation the merge was part of. Ensure that paths which clean out other temporary operation-specific files (e.g. CHERRY_PICK_HEAD, MERGE_MSG, rebase-merge/ state directory) also clean out this AUTO_MERGE file. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- branch.c | 1 + builtin/rebase.c | 1 + merge-ort.c | 10 ++++++++++ path.c | 1 + path.h | 2 ++ sequencer.c | 5 +++++ 6 files changed, 20 insertions(+) diff --git a/branch.c b/branch.c index 9c9dae1eae321c..b71a2de29dbed9 100644 --- a/branch.c +++ b/branch.c @@ -344,6 +344,7 @@ void remove_merge_branch_state(struct repository *r) unlink(git_path_merge_rr(r)); unlink(git_path_merge_msg(r)); unlink(git_path_merge_mode(r)); + unlink(git_path_auto_merge(r)); save_autostash(git_path_merge_autostash(r)); } diff --git a/builtin/rebase.c b/builtin/rebase.c index 840dbd7eb7772e..6c252d62758c5a 100644 --- a/builtin/rebase.c +++ b/builtin/rebase.c @@ -737,6 +737,7 @@ static int finish_rebase(struct rebase_options *opts) int ret = 0; delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF); + unlink(git_path_auto_merge(the_repository)); apply_autostash(state_dir_path("autostash", opts)); close_object_store(the_repository->objects); /* diff --git a/merge-ort.c b/merge-ort.c index 303e894142743e..e8f1a435f99ae0 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -3496,6 +3496,9 @@ void merge_switch_to_result(struct merge_options *opt, { assert(opt->priv == NULL); if (result->clean >= 0 && update_worktree_and_index) { + const char *filename; + FILE *fp; + trace2_region_enter("merge", "checkout", opt->repo); if (checkout(opt, head, result->tree)) { /* failure to function */ @@ -3514,6 +3517,13 @@ void merge_switch_to_result(struct merge_options *opt, } opt->priv = NULL; trace2_region_leave("merge", "record_conflicted", opt->repo); + + trace2_region_enter("merge", "write_auto_merge", opt->repo); + filename = git_path_auto_merge(opt->repo); + fp = xfopen(filename, "w"); + fprintf(fp, "%s\n", oid_to_hex(&result->tree->object.oid)); + fclose(fp); + trace2_region_leave("merge", "write_auto_merge", opt->repo); } if (display_update_msgs) { diff --git a/path.c b/path.c index 7b385e5eb28227..9e883eb52446d3 100644 --- a/path.c +++ b/path.c @@ -1534,5 +1534,6 @@ REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR") REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE") REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD") REPO_GIT_PATH_FUNC(merge_autostash, "MERGE_AUTOSTASH") +REPO_GIT_PATH_FUNC(auto_merge, "AUTO_MERGE") REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD") REPO_GIT_PATH_FUNC(shallow, "shallow") diff --git a/path.h b/path.h index e7e77da6aaa5cf..251c78d980000a 100644 --- a/path.h +++ b/path.h @@ -176,6 +176,7 @@ struct path_cache { const char *merge_mode; const char *merge_head; const char *merge_autostash; + const char *auto_merge; const char *fetch_head; const char *shallow; }; @@ -191,6 +192,7 @@ const char *git_path_merge_rr(struct repository *r); const char *git_path_merge_mode(struct repository *r); const char *git_path_merge_head(struct repository *r); const char *git_path_merge_autostash(struct repository *r); +const char *git_path_auto_merge(struct repository *r); const char *git_path_fetch_head(struct repository *r); const char *git_path_shallow(struct repository *r); diff --git a/sequencer.c b/sequencer.c index d2332d3e178712..472cdd8c620de8 100644 --- a/sequencer.c +++ b/sequencer.c @@ -2096,6 +2096,7 @@ static int do_pick_commit(struct repository *r, refs_delete_ref(get_main_ref_store(r), "", "CHERRY_PICK_HEAD", NULL, 0); unlink(git_path_merge_msg(r)); + unlink(git_path_auto_merge(r)); fprintf(stderr, _("dropping %s %s -- patch contents already upstream\n"), oid_to_hex(&commit->object.oid), msg.subject); @@ -2451,6 +2452,8 @@ void sequencer_post_commit_cleanup(struct repository *r, int verbose) need_cleanup = 1; } + unlink(git_path_auto_merge(r)); + if (!need_cleanup) return; @@ -4111,6 +4114,7 @@ static int pick_commits(struct repository *r, unlink(rebase_path_stopped_sha()); unlink(rebase_path_amend()); unlink(git_path_merge_head(r)); + unlink(git_path_auto_merge(r)); delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF); if (item->command == TODO_BREAK) { @@ -4505,6 +4509,7 @@ static int commit_staged_changes(struct repository *r, return error(_("could not commit staged changes.")); unlink(rebase_path_amend()); unlink(git_path_merge_head(r)); + unlink(git_path_auto_merge(r)); if (final_fixup) { unlink(rebase_path_fixup_msg()); unlink(rebase_path_squash_msg()); From 816147e7bab0c7e9c3a578ce166c55d5f7a64a8a Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:53 +0000 Subject: [PATCH 10/13] merge-recursive: add a bunch of FIXME comments documenting known bugs The plan is to just delete merge-recursive, but not until everyone is comfortable with merge-ort as a replacement. Given that I haven't switched all callers of merge-recursive over yet (e.g. git-am still uses merge-recursive), maybe there's some value documenting known bugs in the algorithm in case we end up keeping it or someone wants to dig it up in the future. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-recursive.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/merge-recursive.c b/merge-recursive.c index b052974f191cd8..99a197597db5c7 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -1075,6 +1075,11 @@ static int merge_3way(struct merge_options *opt, read_mmblob(&src1, &a->oid); read_mmblob(&src2, &b->oid); + /* + * FIXME: Using a->path for normalization rules in ll_merge could be + * wrong if we renamed from a->path to b->path. We should use the + * target path for where the file will be written. + */ merge_status = ll_merge(result_buf, a->path, &orig, base, &src1, name1, &src2, name2, opt->repo->index, &ll_opts); @@ -1154,6 +1159,8 @@ static void print_commit(struct commit *commit) struct strbuf sb = STRBUF_INIT; struct pretty_print_context ctx = {0}; ctx.date_mode.type = DATE_NORMAL; + /* FIXME: Merge this with output_commit_title() */ + assert(!merge_remote_util(commit)); format_commit_message(commit, " %h: %m %s", &sb, &ctx); fprintf(stderr, "%s\n", sb.buf); strbuf_release(&sb); @@ -1177,6 +1184,11 @@ static int merge_submodule(struct merge_options *opt, int search = !opt->priv->call_depth; /* store a in result in case we fail */ + /* FIXME: This is the WRONG resolution for the recursive case when + * we need to be careful to avoid accidentally matching either side. + * Should probably use o instead there, much like we do for merging + * binaries. + */ oidcpy(result, a); /* we can not handle deletion conflicts */ @@ -1301,6 +1313,13 @@ static int merge_mode_and_contents(struct merge_options *opt, if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) { result->clean = 0; + /* + * FIXME: This is a bad resolution for recursive case; for + * the recursive case we want something that is unlikely to + * accidentally match either side. Also, while it makes + * sense to prefer regular files over symlinks, it doesn't + * make sense to prefer regular files over submodules. + */ if (S_ISREG(a->mode)) { result->blob.mode = a->mode; oidcpy(&result->blob.oid, &a->oid); @@ -1349,6 +1368,7 @@ static int merge_mode_and_contents(struct merge_options *opt, free(result_buf.ptr); if (ret) return ret; + /* FIXME: bug, what if modes didn't match? */ result->clean = (merge_status == 0); } else if (S_ISGITLINK(a->mode)) { result->clean = merge_submodule(opt, &result->blob.oid, @@ -2664,6 +2684,14 @@ static int process_renames(struct merge_options *opt, struct string_list b_by_dst = STRING_LIST_INIT_NODUP; const struct rename *sre; + /* + * FIXME: As string-list.h notes, it's O(n^2) to build a sorted + * string_list one-by-one, but O(n log n) to build it unsorted and + * then sort it. Note that as we build the list, we do not need to + * check if the existing destination path is already in the list, + * because the structure of diffcore_rename guarantees we won't + * have duplicates. + */ for (i = 0; i < a_renames->nr; i++) { sre = a_renames->items[i].util; string_list_insert(&a_by_dst, sre->pair->two->path)->util @@ -3602,6 +3630,15 @@ static int merge_recursive_internal(struct merge_options *opt, return err(opt, _("merge returned no commit")); } + /* + * FIXME: Since merge_recursive_internal() is only ever called by + * places that ensure the index is loaded first + * (e.g. builtin/merge.c, rebase/sequencer, etc.), in the common + * case where the merge base was unique that means when we get here + * we immediately discard the index and re-read it, which is a + * complete waste of time. We should only be discarding and + * re-reading if we were forced to recurse. + */ discard_index(opt->repo->index); if (!opt->priv->call_depth) repo_read_index(opt->repo); From 41376b58e6332796343a76b222334901207065ae Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:54 +0000 Subject: [PATCH 11/13] Revert "merge-ort: ignore the directory rename split conflict for now" This reverts commit 5ced7c3da009090c5a926e3123a71314c7f28d42, which was put in place as a temporary measure to avoid optimizations unstably erroring out on no destination having a majority of the necessary renames for directories that had no new files and thus no need for directory rename detection anyway. Now that optimizations are in place to prevent us from trying to compute directory rename count computations for directories that do not need it, we can undo this temporary measure. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- merge-ort.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) diff --git a/merge-ort.c b/merge-ort.c index e8f1a435f99ae0..8258d3fd621e0f 100644 --- a/merge-ort.c +++ b/merge-ort.c @@ -1636,18 +1636,7 @@ static void get_provisional_directory_renames(struct merge_options *opt, "no destination getting a majority of the " "files."), source_dir); - /* - * We should mark this as unclean IF something attempts - * to use this rename. We do not yet have the logic - * in place to detect if this directory rename is being - * used, and optimizations that reduce the number of - * renames cause this to falsely trigger. For now, - * just disable it, causing t6423 testcase 2a to break. - * We'll later fix the detection, and when we do we - * will re-enable setting *clean to 0 (and thereby fix - * t6423 testcase 2a). - */ - /* *clean = 0; */ + *clean = 0; } else { strmap_put(&renames->dir_renames[side], source_dir, (void*)best); From 259490e572b630c15c882d964b146424cc26614d Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:55 +0000 Subject: [PATCH 12/13] t6423: mark remaining expected failure under merge-ort as such When we started on merge-ort, thousands of tests failed when run with the GIT_TEST_MERGE_ALGORITHM=ort flag; with so many, it didn't make sense to flip all their test expectations. The ones in t6409, t6418, and the submodule tests are being handled by an independent in-flight topic ("Complete merge-ort implemenation...almost"). The ones in t6423 were left out of the other series because other ongoing series that this commit depends upon were addressing those. Now that we only have one remaining test failure in t6423, let's mark it as such. This remaining test will be fixed by a future optimization series, but since merge-recursive doesn't pass this test either, passing it is not necessary for declaring merge-ort ready for general use. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- t/t6423-merge-rename-directories.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/t/t6423-merge-rename-directories.sh b/t/t6423-merge-rename-directories.sh index 4c568050dd2767..4c3d0b95dc5c6f 100755 --- a/t/t6423-merge-rename-directories.sh +++ b/t/t6423-merge-rename-directories.sh @@ -4797,7 +4797,7 @@ test_setup_12f () { ) } -test_expect_merge_algorithm failure success '12f: Trivial directory resolve, caching, all kinds of fun' ' +test_expect_merge_algorithm failure failure '12f: Trivial directory resolve, caching, all kinds of fun' ' test_setup_12f && ( cd 12f && From f3b964a07ef70eee6bacefd1ed5f94eb871be902 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sat, 20 Mar 2021 00:03:56 +0000 Subject: [PATCH 13/13] Add testing with merge-ort merge strategy In preparation for switching from merge-recursive to merge-ort as the default strategy, have the testsuite default to running with merge-ort. Keep coverage of the recursive backend by having the linux-gcc job run with it. Signed-off-by: Elijah Newren Reviewed-by: Derrick Stolee Signed-off-by: Junio C Hamano --- ci/run-build-and-tests.sh | 1 + t/test-lib.sh | 2 ++ 2 files changed, 3 insertions(+) diff --git a/ci/run-build-and-tests.sh b/ci/run-build-and-tests.sh index 50e0b90073f133..2279ff70a735b9 100755 --- a/ci/run-build-and-tests.sh +++ b/ci/run-build-and-tests.sh @@ -16,6 +16,7 @@ linux-gcc) export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main make test export GIT_TEST_SPLIT_INDEX=yes + export GIT_TEST_MERGE_ALGORITHM=recursive export GIT_TEST_FULL_IN_PACK_ARRAY=true export GIT_TEST_OE_SIZE=10 export GIT_TEST_OE_DELTA_SIZE=5 diff --git a/t/test-lib.sh b/t/test-lib.sh index 431adba0fb3f8e..6f4185037183ac 100644 --- a/t/test-lib.sh +++ b/t/test-lib.sh @@ -448,6 +448,8 @@ export EDITOR GIT_DEFAULT_HASH="${GIT_TEST_DEFAULT_HASH:-sha1}" export GIT_DEFAULT_HASH +GIT_TEST_MERGE_ALGORITHM="${GIT_TEST_MERGE_ALGORITHM:-ort}" +export GIT_TEST_MERGE_ALGORITHM # Tests using GIT_TRACE typically don't want : output GIT_TRACE_BARE=1