From e8861ffc203fe5ea3da97210e60b2e886002f218 Mon Sep 17 00:00:00 2001 From: Aaron Lipman Date: Fri, 7 Aug 2020 17:58:37 -0400 Subject: [PATCH] bisect: introduce first-parent flag Upon seeing a merge commit when bisecting, this option may be used to follow only the first parent. In detecting regressions introduced through the merging of a branch, the merge commit will be identified as introduction of the bug and its ancestors will be ignored. This option is particularly useful in avoiding false positives when a merged branch contained broken or non-buildable commits, but the merge itself was OK. Signed-off-by: Aaron Lipman Signed-off-by: Junio C Hamano --- Documentation/git-bisect.txt | 13 ++++++++++++- bisect.c | 5 ++++- builtin/bisect--helper.c | 9 ++++++++- t/t6030-bisect-porcelain.sh | 18 ++++++++++++++++++ 4 files changed, 42 insertions(+), 3 deletions(-) diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt index 7586c5a843..0e993e4587 100644 --- a/Documentation/git-bisect.txt +++ b/Documentation/git-bisect.txt @@ -17,7 +17,7 @@ The command takes various subcommands, and different options depending on the subcommand: git bisect start [--term-{old,good}= --term-{new,bad}=] - [--no-checkout] [ [...]] [--] [...] + [--no-checkout] [--first-parent] [ [...]] [--] [...] git bisect (bad|new|) [] git bisect (good|old|) [...] git bisect terms [--term-good | --term-bad] @@ -365,6 +365,17 @@ does not require a checked out tree. + If the repository is bare, `--no-checkout` is assumed. +--first-parent:: ++ +Follow only the first parent commit upon seeing a merge commit. ++ +In detecting regressions introduced through the merging of a branch, the merge +commit will be identified as introduction of the bug and its ancestors will be +ignored. ++ +This option is particularly useful in avoiding false positives when a merged +branch contained broken or non-buildable commits, but the merge itself was OK. + EXAMPLES -------- diff --git a/bisect.c b/bisect.c index 950ff6f533..bc4241b51f 100644 --- a/bisect.c +++ b/bisect.c @@ -15,6 +15,7 @@ #include "commit-slab.h" #include "commit-reach.h" #include "object-store.h" +#include "dir.h" static struct oid_array good_revs; static struct oid_array skipped_revs; @@ -460,6 +461,7 @@ static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN") static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START") static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG") static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS") +static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT") static GIT_PATH_FUNC(git_path_head_name, "head-name") static void read_bisect_paths(struct argv_array *array) @@ -998,7 +1000,7 @@ enum bisect_error bisect_next_all(struct repository *r, const char *prefix) struct object_id *bisect_rev; char *steps_msg; int no_checkout = ref_exists("BISECT_HEAD"); - int first_parent_only = 0; /* TODO: pass --first-parent flag from git bisect start */ + int first_parent_only = file_exists(git_path_bisect_first_parent()); read_bisect_terms(&term_bad, &term_good); if (read_bisect_refs()) @@ -1142,6 +1144,7 @@ int bisect_clean_state(void) unlink_or_warn(git_path_bisect_names()); unlink_or_warn(git_path_bisect_run()); unlink_or_warn(git_path_bisect_terms()); + unlink_or_warn(git_path_bisect_first_parent()); /* Cleanup head-name if it got left by an old version of git-bisect */ unlink_or_warn(git_path_head_name()); /* diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c index 4b175d1c05..68f8721528 100644 --- a/builtin/bisect--helper.c +++ b/builtin/bisect--helper.c @@ -17,6 +17,7 @@ static GIT_PATH_FUNC(git_path_bisect_head, "BISECT_HEAD") static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG") static GIT_PATH_FUNC(git_path_head_name, "head-name") static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES") +static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT") static const char * const git_bisect_helper_usage[] = { N_("git bisect--helper --next-all"), @@ -28,7 +29,7 @@ static const char * const git_bisect_helper_usage[] = { N_("git bisect--helper --bisect-next-check []"), N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"), N_("git bisect--helper --bisect-start [--term-{old,good}= --term-{new,bad}=]" - "[--no-checkout] [ [...]] [--] [...]"), + " [--no-checkout] [--first-parent] [ [...]] [--] [...]"), NULL }; @@ -424,6 +425,7 @@ static int bisect_append_log_quoted(const char **argv) static int bisect_start(struct bisect_terms *terms, const char **argv, int argc) { int no_checkout = 0; + int first_parent_only = 0; int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0; int flags, pathspec_pos, res = 0; struct string_list revs = STRING_LIST_INIT_DUP; @@ -453,6 +455,8 @@ static int bisect_start(struct bisect_terms *terms, const char **argv, int argc) break; } else if (!strcmp(arg, "--no-checkout")) { no_checkout = 1; + } else if (!strcmp(arg, "--first-parent")) { + first_parent_only = 1; } else if (!strcmp(arg, "--term-good") || !strcmp(arg, "--term-old")) { i++; @@ -577,6 +581,9 @@ static int bisect_start(struct bisect_terms *terms, const char **argv, int argc) */ write_file(git_path_bisect_start(), "%s\n", start_head.buf); + if (first_parent_only) + write_file(git_path_bisect_first_parent(), "\n"); + if (no_checkout) { if (get_oid(start_head.buf, &oid) < 0) { res = error(_("invalid ref: '%s'"), start_head.buf); diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh index a66c4b89bc..b886529e59 100755 --- a/t/t6030-bisect-porcelain.sh +++ b/t/t6030-bisect-porcelain.sh @@ -448,6 +448,24 @@ test_expect_success 'many merge bases creation' ' grep "$SIDE_HASH5" merge_bases.txt ' +# We want to automatically find the merge that +# added "line" into hello. +test_expect_success '"git bisect run --first-parent" simple case' ' + git rev-list --first-parent $B_HASH ^$HASH4 >first_parent_chain.txt && + write_script test_script.sh <<-\EOF && + grep $(git rev-parse HEAD) first_parent_chain.txt || exit -1 + ! grep line hello >/dev/null + EOF + git bisect start --first-parent && + test_path_is_file ".git/BISECT_FIRST_PARENT" && + git bisect good $HASH4 && + git bisect bad $B_HASH && + git bisect run ./test_script.sh >my_bisect_log.txt && + grep "$B_HASH is the first bad commit" my_bisect_log.txt && + git bisect reset && + test_path_is_missing .git/BISECT_FIRST_PARENT +' + test_expect_success 'good merge bases when good and bad are siblings' ' git bisect start "$B_HASH" "$A_HASH" > my_bisect_log.txt && test_i18ngrep "merge base must be tested" my_bisect_log.txt &&