| Message ID | b3ae62083e14aecdfe909735b4daf0a36fa5e48c.1640419159.git.gitgitgadget@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add a new --remerge-diff capability to show & log | expand |
On Sat, Dec 25, 2021 at 07:59:12AM +0000, Elijah Newren via GitGitGadget wrote: > From: Elijah Newren <newren@gmail.com> > > When this option is specified, we remerge all (two parent) merge commits > and diff the actual merge commit to the automatically created version, > in order to show how users removed conflict markers, resolved the > different conflict versions, and potentially added new changes outside > of conflict regions in order to resolve semantic merge problems (or, > possibly, just to hide other random changes). > > This capability works by creating a temporary object directory and > marking it as the primary object store. This makes it so that any blobs > or trees created during the automatic merge easily removable afterwards s/easily/are easily/ ? > by just deleting all objects from the temporary object directory. > > There are a few ways that this implementation is suboptimal: > * `log --remerge-diff` becomes slow, because the temporary object > directory can fills with many loose objects while running s/can fills/can fill/ > * the log output can be muddied with misplaced "warning: cannot merge > binary files" messages, since ll-merge.c unconditionally writes those > messages to stderr while running instead of allowing callers to > manage them. > * important conflict and warning messages are simply dropped; thus for > conflicts like modify/delete or rename/rename or file/directory which > are not representable with content conflict markers, there may be no > way for a user of --remerge-diff to know that there had been a > conflict which was resolved (and which possibly motivated other > changes in the merge commit). > Subsequent commits will address these issues. > > Signed-off-by: Elijah Newren <newren@gmail.com> > --- > Documentation/diff-options.txt | 8 ++++ > builtin/log.c | 14 ++++++ > diff-merges.c | 12 +++++ > log-tree.c | 59 +++++++++++++++++++++++ > revision.h | 3 +- > t/t4069-remerge-diff.sh | 86 ++++++++++++++++++++++++++++++++++ > 6 files changed, 181 insertions(+), 1 deletion(-) > create mode 100755 t/t4069-remerge-diff.sh > > diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt > index c89d530d3d1..b05f1c9f1c9 100644 > --- a/Documentation/diff-options.txt > +++ b/Documentation/diff-options.txt > @@ -64,6 +64,14 @@ ifdef::git-log[] > each of the parents. Separate log entry and diff is generated > for each parent. > + > +--diff-merges=remerge::: > +--diff-merges=r::: > +--remerge-diff::: The synopsis above needs an update, too: diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index c89d530d3d..7a98ab3f85 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -36,3 +36,3 @@ endif::git-format-patch[] ifdef::git-log[] ---diff-merges=(off|none|on|first-parent|1|separate|m|combined|c|dense-combined|cc):: +--diff-merges=(off|none|on|first-parent|1|separate|m|combined|c|dense-combined|cc|remerge|r):: --no-diff-merges:: > + With this option, two-parent merge commits are remerged to > + create a temporary tree object -- potentially containing files > + with conflict markers and such. A diff is then shown between > + that temporary tree and the actual merge commit. I had not really looked at any of the --diff-merges options before. The term "remerge" felt a bit opaque at first, because I didn't know what the diff would look like. I might have found this easier: --diff-merges=resolution::: --diff-merges=r::: --resolution-diff::: This makes two-parent merge commits show the diff with respect to a mechanical merge of their parents -- potentially containing files with conflict markers and such. But on a second thought, remerge is actually consistent with the rest, because it states _what_ we compare to the merge commit, so nevermind. > ++ > --diff-merges=combined::: > --diff-merges=c::: > -c::: > diff --git a/builtin/log.c b/builtin/log.c > index f75d87e8d7f..d053418fddd 100644 > --- a/builtin/log.c > +++ b/builtin/log.c > @@ -35,6 +35,7 @@ > #include "repository.h" > #include "commit-reach.h" > #include "range-diff.h" > +#include "tmp-objdir.h" > > #define MAIL_DEFAULT_WRAP 72 > #define COVER_FROM_AUTO_MAX_SUBJECT_LEN 100 > @@ -406,6 +407,14 @@ static int cmd_log_walk(struct rev_info *rev) > struct commit *commit; > int saved_nrl = 0; > int saved_dcctc = 0; > + struct tmp_objdir *remerge_objdir = NULL; > + > + if (rev->remerge_diff) { > + remerge_objdir = tmp_objdir_create("remerge-diff"); > + if (!remerge_objdir) > + die_errno(_("unable to create temporary object directory")); > + tmp_objdir_replace_primary_odb(remerge_objdir, 1); > + } > > if (rev->early_output) > setup_early_output(); > @@ -449,6 +458,9 @@ static int cmd_log_walk(struct rev_info *rev) > rev->diffopt.no_free = 0; > diff_free(&rev->diffopt); > > + if (rev->remerge_diff) > + tmp_objdir_destroy(remerge_objdir); > + > if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF && > rev->diffopt.flags.check_failed) { > return 02; > @@ -1943,6 +1955,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix) > die(_("--name-status does not make sense")); > if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF) > die(_("--check does not make sense")); > + if (rev.remerge_diff) > + die(_("--remerge-diff does not make sense")); > > if (!use_patch_format && > (!rev.diffopt.output_format || > diff --git a/diff-merges.c b/diff-merges.c > index 5060ccd890b..0af4b3f9191 100644 > --- a/diff-merges.c > +++ b/diff-merges.c > @@ -17,6 +17,7 @@ static void suppress(struct rev_info *revs) > revs->combined_all_paths = 0; > revs->merges_imply_patch = 0; > revs->merges_need_diff = 0; > + revs->remerge_diff = 0; > } > > static void set_separate(struct rev_info *revs) > @@ -45,6 +46,12 @@ static void set_dense_combined(struct rev_info *revs) > revs->dense_combined_merges = 1; > } > > +static void set_remerge_diff(struct rev_info *revs) > +{ > + suppress(revs); > + revs->remerge_diff = 1; > +} > + > static diff_merges_setup_func_t func_by_opt(const char *optarg) > { > if (!strcmp(optarg, "off") || !strcmp(optarg, "none")) > @@ -57,6 +64,8 @@ static diff_merges_setup_func_t func_by_opt(const char *optarg) > return set_combined; > else if (!strcmp(optarg, "cc") || !strcmp(optarg, "dense-combined")) > return set_dense_combined; > + else if (!strcmp(optarg, "r") || !strcmp(optarg, "remerge")) > + return set_remerge_diff; > else if (!strcmp(optarg, "m") || !strcmp(optarg, "on")) > return set_to_default; > return NULL; > @@ -110,6 +119,9 @@ int diff_merges_parse_opts(struct rev_info *revs, const char **argv) > } else if (!strcmp(arg, "--cc")) { > set_dense_combined(revs); > revs->merges_imply_patch = 1; > + } else if (!strcmp(arg, "--remerge-diff")) { > + set_remerge_diff(revs); > + revs->merges_imply_patch = 1; > } else if (!strcmp(arg, "--no-diff-merges")) { > suppress(revs); > } else if (!strcmp(arg, "--combined-all-paths")) { > diff --git a/log-tree.c b/log-tree.c > index 644893fd8cf..84ed864fc81 100644 > --- a/log-tree.c > +++ b/log-tree.c > @@ -1,4 +1,5 @@ > #include "cache.h" > +#include "commit-reach.h" > #include "config.h" > #include "diff.h" > #include "object-store.h" > @@ -7,6 +8,7 @@ > #include "tag.h" > #include "graph.h" > #include "log-tree.h" > +#include "merge-ort.h" > #include "reflog-walk.h" > #include "refs.h" > #include "string-list.h" > @@ -902,6 +904,51 @@ static int do_diff_combined(struct rev_info *opt, struct commit *commit) > return !opt->loginfo; > } > > +static int do_remerge_diff(struct rev_info *opt, > + struct commit_list *parents, > + struct object_id *oid, > + struct commit *commit) > +{ > + struct merge_options o; > + struct commit_list *bases; > + struct merge_result res = {0}; > + struct pretty_print_context ctx = {0}; > + struct commit *parent1 = parents->item; > + struct commit *parent2 = parents->next->item; > + struct strbuf parent1_desc = STRBUF_INIT; > + struct strbuf parent2_desc = STRBUF_INIT; > + > + /* Setup merge options */ > + init_merge_options(&o, the_repository); > + o.show_rename_progress = 0; Is there a reason why we are repeating the default here (but not anywhere else)? For example sequencer.c::do_merge() and builtin/am.c::fall_back_threeway() don't, and probably also rely on this being disabled(?). > + > + ctx.abbrev = DEFAULT_ABBREV; > + format_commit_message(parent1, "%h (%s)", &parent1_desc, &ctx); > + format_commit_message(parent2, "%h (%s)", &parent2_desc, &ctx); > + o.branch1 = parent1_desc.buf; > + o.branch2 = parent2_desc.buf; > + > + /* Parse the relevant commits and get the merge bases */ > + parse_commit_or_die(parent1); > + parse_commit_or_die(parent2); > + bases = get_merge_bases(parent1, parent2); > + > + /* Re-merge the parents */ > + merge_incore_recursive(&o, bases, parent1, parent2, &res); > + > + /* Show the diff */ > + diff_tree_oid(&res.tree->object.oid, oid, "", &opt->diffopt); > + log_tree_diff_flush(opt); > + > + /* Cleanup */ > + strbuf_release(&parent1_desc); > + strbuf_release(&parent2_desc); > + merge_finalize(&o, &res); > + /* TODO: clean up the temporary object directory */ > + > + return !opt->loginfo; > +} > + > /* > * Show the diff of a commit. > * > @@ -936,6 +983,18 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log > } > > if (is_merge) { > + int octopus = (parents->next->next != NULL); > + > + if (opt->remerge_diff) { > + if (octopus) { > + show_log(opt); > + fprintf(opt->diffopt.file, > + "diff: warning: Skipping remerge-diff " > + "for octopus merges.\n"); > + return 1; > + } > + return do_remerge_diff(opt, parents, oid, commit); > + } > if (opt->combine_merges) > return do_diff_combined(opt, commit); > if (opt->separate_merges) { > diff --git a/revision.h b/revision.h > index 5578bb4720a..13178e6b8f3 100644 > --- a/revision.h > +++ b/revision.h > @@ -195,7 +195,8 @@ struct rev_info { > combine_merges:1, > combined_all_paths:1, > dense_combined_merges:1, > - first_parent_merges:1; > + first_parent_merges:1, > + remerge_diff:1; > > /* Format info */ > int show_notes; > diff --git a/t/t4069-remerge-diff.sh b/t/t4069-remerge-diff.sh > new file mode 100755 > index 00000000000..192dbce2bfe > --- /dev/null > +++ b/t/t4069-remerge-diff.sh > @@ -0,0 +1,86 @@ > +#!/bin/sh > + > +test_description='remerge-diff handling' > + > +. ./test-lib.sh > + > +test_expect_success 'setup basic merges' ' > + test_write_lines 1 2 3 4 5 6 7 8 9 >numbers && > + git add numbers && > + git commit -m base && > + > + git branch feature_a && > + git branch feature_b && > + git branch feature_c && > + > + git branch ab_resolution && > + git branch bc_resolution && > + > + git checkout feature_a && > + test_write_lines 1 2 three 4 5 6 7 eight 9 >numbers && > + git commit -a -m change_a && > + > + git checkout feature_b && > + test_write_lines 1 2 tres 4 5 6 7 8 9 >numbers && > + git commit -a -m change_b && > + > + git checkout feature_c && > + test_write_lines 1 2 3 4 5 6 7 8 9 10 >numbers && > + git commit -a -m change_c && > + > + git checkout bc_resolution && > + # fast forward > + git merge feature_b && maybe use --ff-only instead of the comment? Same below. (But if we did that we probably want to drop the "no conflict" comment too.) > + # no conflict > + git merge feature_c && > + > + git checkout ab_resolution && > + # fast forward > + git merge feature_a && > + # conflicts! > + test_must_fail git merge feature_b && > + # Resolve conflict...and make another change elsewhere > + test_write_lines 1 2 drei 4 5 6 7 acht 9 >numbers && > + git add numbers && > + git merge --continue > +' > + > +test_expect_success 'remerge-diff on a clean merge' ' > + git log -1 --oneline bc_resolution >expect && > + git show --oneline --remerge-diff bc_resolution >actual && > + test_cmp expect actual > +' > + > +test_expect_success 'remerge-diff with both a resolved conflict and an unrelated change' ' > + git log -1 --oneline ab_resolution >tmp && > + cat <<-EOF >>tmp && > + diff --git a/numbers b/numbers > + index a1fb731..6875544 100644 > + --- a/numbers > + +++ b/numbers > + @@ -1,13 +1,9 @@ > + 1 > + 2 > + -<<<<<<< b0ed5cb (change_a) > + -three > + -======= > + -tres > + ->>>>>>> 6cd3f82 (change_b) > + +drei nice > + 4 > + 5 > + 6 > + 7 > + -eight > + +acht > + 9 > + EOF > + # Hashes above are sha1; rip them out so test works with sha256 > + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >expect && Right, sha256 could cause many noisy test changes. I wonder if there is a more general way to avoid this; maybe default to SHA1 for existing tests? > + > + git show --oneline --remerge-diff ab_resolution >tmp && > + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >actual && > + test_cmp expect actual > +' > + > +test_done > -- > gitgitgadget >
CC'ing brian in case he has comments on the sha256 stuff and whether he thinks there's a cleaner way to make my tests work with sha256. (brian: See the very end of the email.) On Tue, Dec 28, 2021 at 2:56 AM Johannes Altmanninger <aclopte@gmail.com> wrote: > > On Sat, Dec 25, 2021 at 07:59:12AM +0000, Elijah Newren via GitGitGadget wrote: > > From: Elijah Newren <newren@gmail.com> > > > > When this option is specified, we remerge all (two parent) merge commits > > and diff the actual merge commit to the automatically created version, > > in order to show how users removed conflict markers, resolved the > > different conflict versions, and potentially added new changes outside > > of conflict regions in order to resolve semantic merge problems (or, > > possibly, just to hide other random changes). > > > > This capability works by creating a temporary object directory and > > marking it as the primary object store. This makes it so that any blobs > > or trees created during the automatic merge easily removable afterwards > > s/easily/are easily/ ? sure > > by just deleting all objects from the temporary object directory. > > > > There are a few ways that this implementation is suboptimal: > > * `log --remerge-diff` becomes slow, because the temporary object > > directory can fills with many loose objects while running > > s/can fills/can fill/ Thanks. > > > * the log output can be muddied with misplaced "warning: cannot merge > > binary files" messages, since ll-merge.c unconditionally writes those > > messages to stderr while running instead of allowing callers to > > manage them. > > * important conflict and warning messages are simply dropped; thus for > > conflicts like modify/delete or rename/rename or file/directory which > > are not representable with content conflict markers, there may be no > > way for a user of --remerge-diff to know that there had been a > > conflict which was resolved (and which possibly motivated other > > changes in the merge commit). > > Subsequent commits will address these issues. > > > > Signed-off-by: Elijah Newren <newren@gmail.com> > > --- > > Documentation/diff-options.txt | 8 ++++ > > builtin/log.c | 14 ++++++ > > diff-merges.c | 12 +++++ > > log-tree.c | 59 +++++++++++++++++++++++ > > revision.h | 3 +- > > t/t4069-remerge-diff.sh | 86 ++++++++++++++++++++++++++++++++++ > > 6 files changed, 181 insertions(+), 1 deletion(-) > > create mode 100755 t/t4069-remerge-diff.sh > > > > diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt > > index c89d530d3d1..b05f1c9f1c9 100644 > > --- a/Documentation/diff-options.txt > > +++ b/Documentation/diff-options.txt > > @@ -64,6 +64,14 @@ ifdef::git-log[] > > each of the parents. Separate log entry and diff is generated > > for each parent. > > + > > +--diff-merges=remerge::: > > +--diff-merges=r::: > > +--remerge-diff::: > > The synopsis above needs an update, too: > > diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt > index c89d530d3d..7a98ab3f85 100644 > --- a/Documentation/diff-options.txt > +++ b/Documentation/diff-options.txt > @@ -36,3 +36,3 @@ endif::git-format-patch[] > ifdef::git-log[] > ---diff-merges=(off|none|on|first-parent|1|separate|m|combined|c|dense-combined|cc):: > +--diff-merges=(off|none|on|first-parent|1|separate|m|combined|c|dense-combined|cc|remerge|r):: > --no-diff-merges:: Ah, good catch. > > + With this option, two-parent merge commits are remerged to > > + create a temporary tree object -- potentially containing files > > + with conflict markers and such. A diff is then shown between > > + that temporary tree and the actual merge commit. > > I had not really looked at any of the --diff-merges options before. The term > "remerge" felt a bit opaque at first, because I didn't know what the diff > would look like. I might have found this easier: > > --diff-merges=resolution::: > --diff-merges=r::: > --resolution-diff::: > This makes two-parent merge commits show the diff with respect to > a mechanical merge of their parents -- potentially containing files > with conflict markers and such. > > But on a second thought, remerge is actually consistent with the rest, > because it states _what_ we compare to the merge commit, so nevermind. > > > ++ > > --diff-merges=combined::: > > --diff-merges=c::: > > -c::: > > diff --git a/builtin/log.c b/builtin/log.c > > index f75d87e8d7f..d053418fddd 100644 > > --- a/builtin/log.c > > +++ b/builtin/log.c > > @@ -35,6 +35,7 @@ > > #include "repository.h" > > #include "commit-reach.h" > > #include "range-diff.h" > > +#include "tmp-objdir.h" > > > > #define MAIL_DEFAULT_WRAP 72 > > #define COVER_FROM_AUTO_MAX_SUBJECT_LEN 100 > > @@ -406,6 +407,14 @@ static int cmd_log_walk(struct rev_info *rev) > > struct commit *commit; > > int saved_nrl = 0; > > int saved_dcctc = 0; > > + struct tmp_objdir *remerge_objdir = NULL; > > + > > + if (rev->remerge_diff) { > > + remerge_objdir = tmp_objdir_create("remerge-diff"); > > + if (!remerge_objdir) > > + die_errno(_("unable to create temporary object directory")); > > + tmp_objdir_replace_primary_odb(remerge_objdir, 1); > > + } > > > > if (rev->early_output) > > setup_early_output(); > > @@ -449,6 +458,9 @@ static int cmd_log_walk(struct rev_info *rev) > > rev->diffopt.no_free = 0; > > diff_free(&rev->diffopt); > > > > + if (rev->remerge_diff) > > + tmp_objdir_destroy(remerge_objdir); > > + > > if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF && > > rev->diffopt.flags.check_failed) { > > return 02; > > @@ -1943,6 +1955,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix) > > die(_("--name-status does not make sense")); > > if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF) > > die(_("--check does not make sense")); > > + if (rev.remerge_diff) > > + die(_("--remerge-diff does not make sense")); > > > > if (!use_patch_format && > > (!rev.diffopt.output_format || > > diff --git a/diff-merges.c b/diff-merges.c > > index 5060ccd890b..0af4b3f9191 100644 > > --- a/diff-merges.c > > +++ b/diff-merges.c > > @@ -17,6 +17,7 @@ static void suppress(struct rev_info *revs) > > revs->combined_all_paths = 0; > > revs->merges_imply_patch = 0; > > revs->merges_need_diff = 0; > > + revs->remerge_diff = 0; > > } > > > > static void set_separate(struct rev_info *revs) > > @@ -45,6 +46,12 @@ static void set_dense_combined(struct rev_info *revs) > > revs->dense_combined_merges = 1; > > } > > > > +static void set_remerge_diff(struct rev_info *revs) > > +{ > > + suppress(revs); > > + revs->remerge_diff = 1; > > +} > > + > > static diff_merges_setup_func_t func_by_opt(const char *optarg) > > { > > if (!strcmp(optarg, "off") || !strcmp(optarg, "none")) > > @@ -57,6 +64,8 @@ static diff_merges_setup_func_t func_by_opt(const char *optarg) > > return set_combined; > > else if (!strcmp(optarg, "cc") || !strcmp(optarg, "dense-combined")) > > return set_dense_combined; > > + else if (!strcmp(optarg, "r") || !strcmp(optarg, "remerge")) > > + return set_remerge_diff; > > else if (!strcmp(optarg, "m") || !strcmp(optarg, "on")) > > return set_to_default; > > return NULL; > > @@ -110,6 +119,9 @@ int diff_merges_parse_opts(struct rev_info *revs, const char **argv) > > } else if (!strcmp(arg, "--cc")) { > > set_dense_combined(revs); > > revs->merges_imply_patch = 1; > > + } else if (!strcmp(arg, "--remerge-diff")) { > > + set_remerge_diff(revs); > > + revs->merges_imply_patch = 1; > > } else if (!strcmp(arg, "--no-diff-merges")) { > > suppress(revs); > > } else if (!strcmp(arg, "--combined-all-paths")) { > > diff --git a/log-tree.c b/log-tree.c > > index 644893fd8cf..84ed864fc81 100644 > > --- a/log-tree.c > > +++ b/log-tree.c > > @@ -1,4 +1,5 @@ > > #include "cache.h" > > +#include "commit-reach.h" > > #include "config.h" > > #include "diff.h" > > #include "object-store.h" > > @@ -7,6 +8,7 @@ > > #include "tag.h" > > #include "graph.h" > > #include "log-tree.h" > > +#include "merge-ort.h" > > #include "reflog-walk.h" > > #include "refs.h" > > #include "string-list.h" > > @@ -902,6 +904,51 @@ static int do_diff_combined(struct rev_info *opt, struct commit *commit) > > return !opt->loginfo; > > } > > > > +static int do_remerge_diff(struct rev_info *opt, > > + struct commit_list *parents, > > + struct object_id *oid, > > + struct commit *commit) > > +{ > > + struct merge_options o; > > + struct commit_list *bases; > > + struct merge_result res = {0}; > > + struct pretty_print_context ctx = {0}; > > + struct commit *parent1 = parents->item; > > + struct commit *parent2 = parents->next->item; > > + struct strbuf parent1_desc = STRBUF_INIT; > > + struct strbuf parent2_desc = STRBUF_INIT; > > + > > + /* Setup merge options */ > > + init_merge_options(&o, the_repository); > > + o.show_rename_progress = 0; > > Is there a reason why we are repeating the default here (but not anywhere else)? > For example sequencer.c::do_merge() and builtin/am.c::fall_back_threeway() > don't, and probably also rely on this being disabled(?). No, I think each of rebase, am, and merge could sensibly have progress output be shown -- whether or not they do currently. Whether or not showing progress is the default now or in the future, though, we don't want it for remerge diff. So, yes, I explicitly made sure to turn it off. > > + > > + ctx.abbrev = DEFAULT_ABBREV; > > + format_commit_message(parent1, "%h (%s)", &parent1_desc, &ctx); > > + format_commit_message(parent2, "%h (%s)", &parent2_desc, &ctx); > > + o.branch1 = parent1_desc.buf; > > + o.branch2 = parent2_desc.buf; > > + > > + /* Parse the relevant commits and get the merge bases */ > > + parse_commit_or_die(parent1); > > + parse_commit_or_die(parent2); > > + bases = get_merge_bases(parent1, parent2); > > + > > + /* Re-merge the parents */ > > + merge_incore_recursive(&o, bases, parent1, parent2, &res); > > + > > + /* Show the diff */ > > + diff_tree_oid(&res.tree->object.oid, oid, "", &opt->diffopt); > > + log_tree_diff_flush(opt); > > + > > + /* Cleanup */ > > + strbuf_release(&parent1_desc); > > + strbuf_release(&parent2_desc); > > + merge_finalize(&o, &res); > > + /* TODO: clean up the temporary object directory */ > > + > > + return !opt->loginfo; > > +} > > + > > /* > > * Show the diff of a commit. > > * > > @@ -936,6 +983,18 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log > > } > > > > if (is_merge) { > > + int octopus = (parents->next->next != NULL); > > + > > + if (opt->remerge_diff) { > > + if (octopus) { > > + show_log(opt); > > + fprintf(opt->diffopt.file, > > + "diff: warning: Skipping remerge-diff " > > + "for octopus merges.\n"); > > + return 1; > > + } > > + return do_remerge_diff(opt, parents, oid, commit); > > + } > > if (opt->combine_merges) > > return do_diff_combined(opt, commit); > > if (opt->separate_merges) { > > diff --git a/revision.h b/revision.h > > index 5578bb4720a..13178e6b8f3 100644 > > --- a/revision.h > > +++ b/revision.h > > @@ -195,7 +195,8 @@ struct rev_info { > > combine_merges:1, > > combined_all_paths:1, > > dense_combined_merges:1, > > - first_parent_merges:1; > > + first_parent_merges:1, > > + remerge_diff:1; > > > > /* Format info */ > > int show_notes; > > diff --git a/t/t4069-remerge-diff.sh b/t/t4069-remerge-diff.sh > > new file mode 100755 > > index 00000000000..192dbce2bfe > > --- /dev/null > > +++ b/t/t4069-remerge-diff.sh > > @@ -0,0 +1,86 @@ > > +#!/bin/sh > > + > > +test_description='remerge-diff handling' > > + > > +. ./test-lib.sh > > + > > +test_expect_success 'setup basic merges' ' > > + test_write_lines 1 2 3 4 5 6 7 8 9 >numbers && > > + git add numbers && > > + git commit -m base && > > + > > + git branch feature_a && > > + git branch feature_b && > > + git branch feature_c && > > + > > + git branch ab_resolution && > > + git branch bc_resolution && > > + > > + git checkout feature_a && > > + test_write_lines 1 2 three 4 5 6 7 eight 9 >numbers && > > + git commit -a -m change_a && > > + > > + git checkout feature_b && > > + test_write_lines 1 2 tres 4 5 6 7 8 9 >numbers && > > + git commit -a -m change_b && > > + > > + git checkout feature_c && > > + test_write_lines 1 2 3 4 5 6 7 8 9 10 >numbers && > > + git commit -a -m change_c && > > + > > + git checkout bc_resolution && > > + # fast forward > > + git merge feature_b && > > maybe use --ff-only instead of the comment? Same below. That'd be fine. > (But if we did that we probably want to drop the "no conflict" comment too.) Nah, I'd rather keep it. > > + # no conflict > > + git merge feature_c && > > + > > + git checkout ab_resolution && > > + # fast forward > > + git merge feature_a && > > + # conflicts! > > + test_must_fail git merge feature_b && > > + # Resolve conflict...and make another change elsewhere > > + test_write_lines 1 2 drei 4 5 6 7 acht 9 >numbers && > > + git add numbers && > > + git merge --continue > > +' > > + > > +test_expect_success 'remerge-diff on a clean merge' ' > > + git log -1 --oneline bc_resolution >expect && > > + git show --oneline --remerge-diff bc_resolution >actual && > > + test_cmp expect actual > > +' > > + > > +test_expect_success 'remerge-diff with both a resolved conflict and an unrelated change' ' > > + git log -1 --oneline ab_resolution >tmp && > > + cat <<-EOF >>tmp && > > + diff --git a/numbers b/numbers > > + index a1fb731..6875544 100644 > > + --- a/numbers > > + +++ b/numbers > > + @@ -1,13 +1,9 @@ > > + 1 > > + 2 > > + -<<<<<<< b0ed5cb (change_a) > > + -three > > + -======= > > + -tres > > + ->>>>>>> 6cd3f82 (change_b) > > + +drei > > nice > > > + 4 > > + 5 > > + 6 > > + 7 > > + -eight > > + +acht > > + 9 > > + EOF > > + # Hashes above are sha1; rip them out so test works with sha256 > > + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >expect && > > Right, sha256 could cause many noisy test changes. I wonder if there is a > more general way to avoid this; maybe default to SHA1 for existing tests? Not "could", but "does". And this is not something to be avoided. The default testsuite we run in CI involves a run of GIT_TEST_DEFAULT_HASH=sha256 under linux-clang. Making these tests SHA1-only just reduces our coverage and makes the transition to SHA256 harder; I think that's the opposite of the direction we want to go. These changes I've made here are sufficient to make these tests work under sha256; you can see the test results here: https://github.com/gitgitgadget/git/runs/4646949283?check_suite_focus=true. Under "Run ci/run-build-and-tests.sh" note that there are two runs of tests, and the second has "export GIT_TEST_DEFAULT_HASH=sha256" preceding it. There might be a cleaner way to make these tests sha256-compatible, but this seemed like a pretty simple way to me.
On 2021-12-28 at 22:34:03, Elijah Newren wrote: > CC'ing brian in case he has comments on the sha256 stuff and whether > he thinks there's a cleaner way to make my tests work with sha256. > (brian: See the very end of the email.) > > On Tue, Dec 28, 2021 at 2:56 AM Johannes Altmanninger <aclopte@gmail.com> wrote: > > > > On Sat, Dec 25, 2021 at 07:59:12AM +0000, Elijah Newren via GitGitGadget wrote: > > > +test_expect_success 'remerge-diff with both a resolved conflict and an unrelated change' ' > > > + git log -1 --oneline ab_resolution >tmp && > > > + cat <<-EOF >>tmp && > > > + diff --git a/numbers b/numbers > > > + index a1fb731..6875544 100644 > > > + --- a/numbers > > > + +++ b/numbers > > > + @@ -1,13 +1,9 @@ > > > + 1 > > > + 2 > > > + -<<<<<<< b0ed5cb (change_a) > > > + -three > > > + -======= > > > + -tres > > > + ->>>>>>> 6cd3f82 (change_b) > > > + +drei > > > > nice > > > > > + 4 > > > + 5 > > > + 6 > > > + 7 > > > + -eight > > > + +acht > > > + 9 > > > + EOF > > > + # Hashes above are sha1; rip them out so test works with sha256 > > > + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >expect && > > > > Right, sha256 could cause many noisy test changes. I wonder if there is a > > more general way to avoid this; maybe default to SHA1 for existing tests? > > Not "could", but "does". And this is not something to be avoided. > The default testsuite we run in CI involves a run of > GIT_TEST_DEFAULT_HASH=sha256 under linux-clang. Making these tests > SHA1-only just reduces our coverage and makes the transition to SHA256 > harder; I think that's the opposite of the direction we want to go. > > These changes I've made here are sufficient to make these tests work > under sha256; you can see the test results here: > https://github.com/gitgitgadget/git/runs/4646949283?check_suite_focus=true. > Under "Run ci/run-build-and-tests.sh" note that there are two runs of > tests, and the second has "export GIT_TEST_DEFAULT_HASH=sha256" > preceding it. > > There might be a cleaner way to make these tests sha256-compatible, > but this seemed like a pretty simple way to me. The question here is, do we care very much about testing these specific hashes? If so, then we should use test_oid_cache to set up some OIDs and make sure they're correct for both SHA-1 and SHA-256, and then replace them in the code with calls to test_oid. However, my impression is that we probably don't care very much about what the specific values are, and in that case, this is completely fine. We do similar things elsewhere in the testsuite.
On Tue, Dec 28, 2021 at 3:01 PM brian m. carlson <sandals@crustytoothpaste.net> wrote: > > On 2021-12-28 at 22:34:03, Elijah Newren wrote: > > CC'ing brian in case he has comments on the sha256 stuff and whether > > he thinks there's a cleaner way to make my tests work with sha256. > > (brian: See the very end of the email.) > > > > On Tue, Dec 28, 2021 at 2:56 AM Johannes Altmanninger <aclopte@gmail.com> wrote: > > > > > > On Sat, Dec 25, 2021 at 07:59:12AM +0000, Elijah Newren via GitGitGadget wrote: > > > > +test_expect_success 'remerge-diff with both a resolved conflict and an unrelated change' ' > > > > + git log -1 --oneline ab_resolution >tmp && > > > > + cat <<-EOF >>tmp && > > > > + diff --git a/numbers b/numbers > > > > + index a1fb731..6875544 100644 > > > > + --- a/numbers > > > > + +++ b/numbers > > > > + @@ -1,13 +1,9 @@ > > > > + 1 > > > > + 2 > > > > + -<<<<<<< b0ed5cb (change_a) > > > > + -three > > > > + -======= > > > > + -tres > > > > + ->>>>>>> 6cd3f82 (change_b) > > > > + +drei > > > > > > nice > > > > > > > + 4 > > > > + 5 > > > > + 6 > > > > + 7 > > > > + -eight > > > > + +acht > > > > + 9 > > > > + EOF > > > > + # Hashes above are sha1; rip them out so test works with sha256 > > > > + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >expect && > > > > > > Right, sha256 could cause many noisy test changes. I wonder if there is a > > > more general way to avoid this; maybe default to SHA1 for existing tests? > > > > Not "could", but "does". And this is not something to be avoided. > > The default testsuite we run in CI involves a run of > > GIT_TEST_DEFAULT_HASH=sha256 under linux-clang. Making these tests > > SHA1-only just reduces our coverage and makes the transition to SHA256 > > harder; I think that's the opposite of the direction we want to go. > > > > These changes I've made here are sufficient to make these tests work > > under sha256; you can see the test results here: > > https://github.com/gitgitgadget/git/runs/4646949283?check_suite_focus=true. > > Under "Run ci/run-build-and-tests.sh" note that there are two runs of > > tests, and the second has "export GIT_TEST_DEFAULT_HASH=sha256" > > preceding it. > > > > There might be a cleaner way to make these tests sha256-compatible, > > but this seemed like a pretty simple way to me. > > The question here is, do we care very much about testing these specific > hashes? If so, then we should use test_oid_cache to set up some OIDs > and make sure they're correct for both SHA-1 and SHA-256, and then > replace them in the code with calls to test_oid. > > However, my impression is that we probably don't care very much about > what the specific values are, and in that case, this is completely fine. > We do similar things elsewhere in the testsuite. Thanks for chiming in. Your impression is right; I don't care about the specific hashes, just the general form of the diff content, so I'll keep it as is.
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt index c89d530d3d1..b05f1c9f1c9 100644 --- a/Documentation/diff-options.txt +++ b/Documentation/diff-options.txt @@ -64,6 +64,14 @@ ifdef::git-log[] each of the parents. Separate log entry and diff is generated for each parent. + +--diff-merges=remerge::: +--diff-merges=r::: +--remerge-diff::: + With this option, two-parent merge commits are remerged to + create a temporary tree object -- potentially containing files + with conflict markers and such. A diff is then shown between + that temporary tree and the actual merge commit. ++ --diff-merges=combined::: --diff-merges=c::: -c::: diff --git a/builtin/log.c b/builtin/log.c index f75d87e8d7f..d053418fddd 100644 --- a/builtin/log.c +++ b/builtin/log.c @@ -35,6 +35,7 @@ #include "repository.h" #include "commit-reach.h" #include "range-diff.h" +#include "tmp-objdir.h" #define MAIL_DEFAULT_WRAP 72 #define COVER_FROM_AUTO_MAX_SUBJECT_LEN 100 @@ -406,6 +407,14 @@ static int cmd_log_walk(struct rev_info *rev) struct commit *commit; int saved_nrl = 0; int saved_dcctc = 0; + struct tmp_objdir *remerge_objdir = NULL; + + if (rev->remerge_diff) { + remerge_objdir = tmp_objdir_create("remerge-diff"); + if (!remerge_objdir) + die_errno(_("unable to create temporary object directory")); + tmp_objdir_replace_primary_odb(remerge_objdir, 1); + } if (rev->early_output) setup_early_output(); @@ -449,6 +458,9 @@ static int cmd_log_walk(struct rev_info *rev) rev->diffopt.no_free = 0; diff_free(&rev->diffopt); + if (rev->remerge_diff) + tmp_objdir_destroy(remerge_objdir); + if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF && rev->diffopt.flags.check_failed) { return 02; @@ -1943,6 +1955,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix) die(_("--name-status does not make sense")); if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF) die(_("--check does not make sense")); + if (rev.remerge_diff) + die(_("--remerge-diff does not make sense")); if (!use_patch_format && (!rev.diffopt.output_format || diff --git a/diff-merges.c b/diff-merges.c index 5060ccd890b..0af4b3f9191 100644 --- a/diff-merges.c +++ b/diff-merges.c @@ -17,6 +17,7 @@ static void suppress(struct rev_info *revs) revs->combined_all_paths = 0; revs->merges_imply_patch = 0; revs->merges_need_diff = 0; + revs->remerge_diff = 0; } static void set_separate(struct rev_info *revs) @@ -45,6 +46,12 @@ static void set_dense_combined(struct rev_info *revs) revs->dense_combined_merges = 1; } +static void set_remerge_diff(struct rev_info *revs) +{ + suppress(revs); + revs->remerge_diff = 1; +} + static diff_merges_setup_func_t func_by_opt(const char *optarg) { if (!strcmp(optarg, "off") || !strcmp(optarg, "none")) @@ -57,6 +64,8 @@ static diff_merges_setup_func_t func_by_opt(const char *optarg) return set_combined; else if (!strcmp(optarg, "cc") || !strcmp(optarg, "dense-combined")) return set_dense_combined; + else if (!strcmp(optarg, "r") || !strcmp(optarg, "remerge")) + return set_remerge_diff; else if (!strcmp(optarg, "m") || !strcmp(optarg, "on")) return set_to_default; return NULL; @@ -110,6 +119,9 @@ int diff_merges_parse_opts(struct rev_info *revs, const char **argv) } else if (!strcmp(arg, "--cc")) { set_dense_combined(revs); revs->merges_imply_patch = 1; + } else if (!strcmp(arg, "--remerge-diff")) { + set_remerge_diff(revs); + revs->merges_imply_patch = 1; } else if (!strcmp(arg, "--no-diff-merges")) { suppress(revs); } else if (!strcmp(arg, "--combined-all-paths")) { diff --git a/log-tree.c b/log-tree.c index 644893fd8cf..84ed864fc81 100644 --- a/log-tree.c +++ b/log-tree.c @@ -1,4 +1,5 @@ #include "cache.h" +#include "commit-reach.h" #include "config.h" #include "diff.h" #include "object-store.h" @@ -7,6 +8,7 @@ #include "tag.h" #include "graph.h" #include "log-tree.h" +#include "merge-ort.h" #include "reflog-walk.h" #include "refs.h" #include "string-list.h" @@ -902,6 +904,51 @@ static int do_diff_combined(struct rev_info *opt, struct commit *commit) return !opt->loginfo; } +static int do_remerge_diff(struct rev_info *opt, + struct commit_list *parents, + struct object_id *oid, + struct commit *commit) +{ + struct merge_options o; + struct commit_list *bases; + struct merge_result res = {0}; + struct pretty_print_context ctx = {0}; + struct commit *parent1 = parents->item; + struct commit *parent2 = parents->next->item; + struct strbuf parent1_desc = STRBUF_INIT; + struct strbuf parent2_desc = STRBUF_INIT; + + /* Setup merge options */ + init_merge_options(&o, the_repository); + o.show_rename_progress = 0; + + ctx.abbrev = DEFAULT_ABBREV; + format_commit_message(parent1, "%h (%s)", &parent1_desc, &ctx); + format_commit_message(parent2, "%h (%s)", &parent2_desc, &ctx); + o.branch1 = parent1_desc.buf; + o.branch2 = parent2_desc.buf; + + /* Parse the relevant commits and get the merge bases */ + parse_commit_or_die(parent1); + parse_commit_or_die(parent2); + bases = get_merge_bases(parent1, parent2); + + /* Re-merge the parents */ + merge_incore_recursive(&o, bases, parent1, parent2, &res); + + /* Show the diff */ + diff_tree_oid(&res.tree->object.oid, oid, "", &opt->diffopt); + log_tree_diff_flush(opt); + + /* Cleanup */ + strbuf_release(&parent1_desc); + strbuf_release(&parent2_desc); + merge_finalize(&o, &res); + /* TODO: clean up the temporary object directory */ + + return !opt->loginfo; +} + /* * Show the diff of a commit. * @@ -936,6 +983,18 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log } if (is_merge) { + int octopus = (parents->next->next != NULL); + + if (opt->remerge_diff) { + if (octopus) { + show_log(opt); + fprintf(opt->diffopt.file, + "diff: warning: Skipping remerge-diff " + "for octopus merges.\n"); + return 1; + } + return do_remerge_diff(opt, parents, oid, commit); + } if (opt->combine_merges) return do_diff_combined(opt, commit); if (opt->separate_merges) { diff --git a/revision.h b/revision.h index 5578bb4720a..13178e6b8f3 100644 --- a/revision.h +++ b/revision.h @@ -195,7 +195,8 @@ struct rev_info { combine_merges:1, combined_all_paths:1, dense_combined_merges:1, - first_parent_merges:1; + first_parent_merges:1, + remerge_diff:1; /* Format info */ int show_notes; diff --git a/t/t4069-remerge-diff.sh b/t/t4069-remerge-diff.sh new file mode 100755 index 00000000000..192dbce2bfe --- /dev/null +++ b/t/t4069-remerge-diff.sh @@ -0,0 +1,86 @@ +#!/bin/sh + +test_description='remerge-diff handling' + +. ./test-lib.sh + +test_expect_success 'setup basic merges' ' + test_write_lines 1 2 3 4 5 6 7 8 9 >numbers && + git add numbers && + git commit -m base && + + git branch feature_a && + git branch feature_b && + git branch feature_c && + + git branch ab_resolution && + git branch bc_resolution && + + git checkout feature_a && + test_write_lines 1 2 three 4 5 6 7 eight 9 >numbers && + git commit -a -m change_a && + + git checkout feature_b && + test_write_lines 1 2 tres 4 5 6 7 8 9 >numbers && + git commit -a -m change_b && + + git checkout feature_c && + test_write_lines 1 2 3 4 5 6 7 8 9 10 >numbers && + git commit -a -m change_c && + + git checkout bc_resolution && + # fast forward + git merge feature_b && + # no conflict + git merge feature_c && + + git checkout ab_resolution && + # fast forward + git merge feature_a && + # conflicts! + test_must_fail git merge feature_b && + # Resolve conflict...and make another change elsewhere + test_write_lines 1 2 drei 4 5 6 7 acht 9 >numbers && + git add numbers && + git merge --continue +' + +test_expect_success 'remerge-diff on a clean merge' ' + git log -1 --oneline bc_resolution >expect && + git show --oneline --remerge-diff bc_resolution >actual && + test_cmp expect actual +' + +test_expect_success 'remerge-diff with both a resolved conflict and an unrelated change' ' + git log -1 --oneline ab_resolution >tmp && + cat <<-EOF >>tmp && + diff --git a/numbers b/numbers + index a1fb731..6875544 100644 + --- a/numbers + +++ b/numbers + @@ -1,13 +1,9 @@ + 1 + 2 + -<<<<<<< b0ed5cb (change_a) + -three + -======= + -tres + ->>>>>>> 6cd3f82 (change_b) + +drei + 4 + 5 + 6 + 7 + -eight + +acht + 9 + EOF + # Hashes above are sha1; rip them out so test works with sha256 + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >expect && + + git show --oneline --remerge-diff ab_resolution >tmp && + sed -e "s/[0-9a-f]\{7,\}/HASH/g" tmp >actual && + test_cmp expect actual +' + +test_done