From a9f5bb83e0341a04c46b2dec27e16c793d6447f8 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sun, 23 Oct 2022 01:28:04 +0000 Subject: [PATCH 1/2] merge-tree: update documentation for differences in -z output The Informational Messages was updated in de90581141 ("merge-ort: optionally produce machine-readable output", 2022-06-18) to provide more detailed and machine parseable output when `-z` is passed, but the Documentation was not updated to reflect these changes. Update it now. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- Documentation/git-merge-tree.txt | 46 +++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 7 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index d6c356740e..9914b1bc0c 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -108,18 +108,50 @@ character instead of a newline character. Informational messages ~~~~~~~~~~~~~~~~~~~~~~ -This always starts with a blank line (or NUL if `-z` is passed) to -separate it from the previous sections, and then has free-form -messages about the merge, such as: +This section provides informational messages, typically about +conflicts. The format of the section varies significantly depending +on whether `-z` is passed. + +If `-z` is passed: + +The output format is zero or more conflict informational records, each +of the form: + + NULNUL + +where is of the form + + NULNULNUL...NUL + +and includes paths (or branch names) affected by the conflict or +informational message in . Also, is a +stable string explaining the type of conflict, such as + + * "Auto-merging" + * "CONFLICT (rename/delete)" + * "CONFLICT (submodule lacks merge base)" + * "CONFLICT (binary)" + +and is a more detailed message about the conflict which often +(but not always) embeds the within it. These +strings may change in future Git versions. Some examples: * "Auto-merging " * "CONFLICT (rename/delete): renamed...but deleted in..." - * "Failed to merge submodule ()" + * "Failed to merge submodule (no merge base)" * "Warning: cannot merge binary files: " -Note that these free-form messages will never have a NUL character -in or between them, even if -z is passed. It is simply a large block -of text taking up the remainder of the output. +If `-z` is NOT passed: + +This section starts with a blank line to separate it from the previous +sections, and then only contains the information +from the previous section (separated by newlines). These are +non-stable strings that should not be parsed by scripts, and are just +meant for human consumption. Also, note that while +strings usually do not contain embedded newlines, they sometimes do. +(However, the free-form messages will never have an embedded NUL +character). So, the entire block of information is meant for human +readers as an agglomeration of all conflict messages. EXIT STATUS ----------- From ec1edbcb56ac05e9980299b05924c5c1b51d68b4 Mon Sep 17 00:00:00 2001 From: Elijah Newren Date: Sun, 23 Oct 2022 01:28:05 +0000 Subject: [PATCH 2/2] merge-tree: support multiple batched merges with --stdin Add an option, --stdin, to merge-tree which will accept lines of input with two branches to merge per line, and which will perform all the merges and give output for each in turn. This option implies -z, and modifies the output to also include a merge status since the exit code of the program can no longer convey that information now that multiple merges are involved. This could be useful, for example, by Git hosting providers. When one branch is updated, one may want to check whether all code reviews targetting that branch can still cleanly merge. Avoiding the overhead of starting up a separate process for each of those code reviews might provide significant savings in a repository with many code reviews. Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano --- Documentation/git-merge-tree.txt | 30 ++++++++++++++++++++++- builtin/merge-tree.c | 42 +++++++++++++++++++++++++++++--- t/t4301-merge-tree-write-tree.sh | 41 +++++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 4 deletions(-) diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 9914b1bc0c..04bcc416e6 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -81,6 +81,31 @@ Whereas for a conflicted merge, the output is by default of the form: These are discussed individually below. +However, there is an exception. If `--stdin` is passed, then there is +an extra section at the beginning, a NUL character at the end, and then +all the sections repeat for each line of input. Thus, if the first merge +is conflicted and the second is clean, the output would be of the form: + + + + + + NUL + + + NUL + +[[MS]] +Merge status +~~~~~~~~~~~~ + +This is an integer status followed by a NUL character. The integer status is: + + 0: merge had conflicts + 1: merge was clean + <0: something prevented the merge from running (e.g. access to repository + objects denied by filesystem) + [[OIDTLT]] OID of toplevel tree ~~~~~~~~~~~~~~~~~~~~ @@ -159,7 +184,10 @@ EXIT STATUS For a successful, non-conflicted merge, the exit status is 0. When the merge has conflicts, the exit status is 1. If the merge is not able to complete (or start) due to some kind of error, the exit status is -something other than 0 or 1 (and the output is unspecified). +something other than 0 or 1 (and the output is unspecified). When +--stdin is passed, the return status is 0 for both successful and +conflicted merges, and something other than 0 or 1 if it cannot complete +all the requested merges. USAGE NOTES ----------- diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index ae5782917b..fe853aa8f9 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -402,6 +402,7 @@ struct merge_tree_options { int allow_unrelated_histories; int show_messages; int name_only; + int use_stdin; }; static int real_merge(struct merge_tree_options *o, @@ -412,6 +413,7 @@ static int real_merge(struct merge_tree_options *o, struct commit_list *merge_bases = NULL; struct merge_options opt; struct merge_result result = { 0 }; + int show_messages = o->show_messages; parent1 = get_merge_parent(branch1); if (!parent1) @@ -443,9 +445,11 @@ static int real_merge(struct merge_tree_options *o, if (result.clean < 0) die(_("failure to merge")); - if (o->show_messages == -1) - o->show_messages = !result.clean; + if (show_messages == -1) + show_messages = !result.clean; + if (o->use_stdin) + printf("%d%c", result.clean, line_termination); printf("%s%c", oid_to_hex(&result.tree->object.oid), line_termination); if (!result.clean) { struct string_list conflicted_files = STRING_LIST_INIT_NODUP; @@ -467,11 +471,13 @@ static int real_merge(struct merge_tree_options *o, } string_list_clear(&conflicted_files, 1); } - if (o->show_messages) { + if (show_messages) { putchar(line_termination); merge_display_update_messages(&opt, line_termination == '\0', &result); } + if (o->use_stdin) + putchar(line_termination); merge_finalize(&opt, &result); return !result.clean; /* result.clean < 0 handled above */ } @@ -505,6 +511,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) &o.allow_unrelated_histories, N_("allow merging unrelated histories"), PARSE_OPT_NONEG), + OPT_BOOL_F(0, "stdin", + &o.use_stdin, + N_("perform multiple merges, one per line of input"), + PARSE_OPT_NONEG), OPT_END() }; @@ -512,6 +522,32 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix) original_argc = argc - 1; /* ignoring argv[0] */ argc = parse_options(argc, argv, prefix, mt_options, merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION); + + /* Handle --stdin */ + if (o.use_stdin) { + struct strbuf buf = STRBUF_INIT; + + if (o.mode == MODE_TRIVIAL) + die(_("--trivial-merge is incompatible with all other options")); + line_termination = '\0'; + while (strbuf_getline_lf(&buf, stdin) != EOF) { + struct strbuf **split; + int result; + + split = strbuf_split(&buf, ' '); + if (!split[0] || !split[1] || split[2]) + die(_("malformed input line: '%s'."), buf.buf); + strbuf_rtrim(split[0]); + result = real_merge(&o, split[0]->buf, split[1]->buf, prefix); + if (result < 0) + die(_("merging cannot continue; got unclean result of %d"), result); + strbuf_list_free(split); + } + strbuf_release(&buf); + return 0; + } + + /* Figure out which mode to use */ switch (o.mode) { default: BUG("unexpected command mode %d", o.mode); diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh index 013b77144b..cac85591b5 100755 --- a/t/t4301-merge-tree-write-tree.sh +++ b/t/t4301-merge-tree-write-tree.sh @@ -819,4 +819,45 @@ test_expect_success SANITY 'merge-ort fails gracefully in a read-only repository test_must_fail git -C read-only merge-tree side1 side2 ' +test_expect_success '--stdin with both a successful and a conflicted merge' ' + printf "side1 side3\nside1 side2" | git merge-tree --stdin >actual && + + git checkout side1^0 && + git merge side3 && + + printf "1\0" >expect && + git rev-parse HEAD^{tree} | lf_to_nul >>expect && + printf "\0" >>expect && + + git checkout side1^0 && + test_must_fail git merge side2 && + sed s/HEAD/side1/ greeting >tmp && + mv tmp greeting && + git add -u && + git mv whatever~HEAD whatever~side1 && + + printf "0\0" >>expect && + git write-tree | lf_to_nul >>expect && + + cat <<-EOF | q_to_tab | lf_to_nul >>expect && + 100644 $(git rev-parse side1~1:greeting) 1Qgreeting + 100644 $(git rev-parse side1:greeting) 2Qgreeting + 100644 $(git rev-parse side2:greeting) 3Qgreeting + 100644 $(git rev-parse side1~1:whatever) 1Qwhatever~side1 + 100644 $(git rev-parse side1:whatever) 2Qwhatever~side1 + EOF + + q_to_nul <<-EOF >>expect && + Q1QgreetingQAuto-mergingQAuto-merging greeting + Q1QgreetingQCONFLICT (contents)QCONFLICT (content): Merge conflict in greeting + Q1QnumbersQAuto-mergingQAuto-merging numbers + Q2Qwhatever~side1QwhateverQCONFLICT (file/directory)QCONFLICT (file/directory): directory in the way of whatever from side1; moving it to whatever~side1 instead. + Q1Qwhatever~side1QCONFLICT (modify/delete)QCONFLICT (modify/delete): whatever~side1 deleted in side2 and modified in side1. Version side1 of whatever~side1 left in tree. + EOF + + printf "\0\0" >>expect && + + test_cmp expect actual +' + test_done