Git Mailing List Archive on lore.kernel.org
 help / color / Atom feed
From: Aaron Lipman <alipman88@gmail.com>
To: git@vger.kernel.org
Cc: Aaron Lipman <alipman88@gmail.com>
Subject: [PATCH v4 4/5] bisect: introduce first-parent flag
Date: Tue,  4 Aug 2020 18:01:12 -0400
Message-ID: <20200804220113.5909-5-alipman88@gmail.com> (raw)
In-Reply-To: <20200804220113.5909-1-alipman88@gmail.com>

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 <alipman88@gmail.com>
---
 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> --term-{new,bad}=<term>]
-		  [--no-checkout] [<bad> [<good>...]] [--] [<paths>...]
+		  [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]
  git bisect (bad|new|<term-new>) [<rev>]
  git bisect (good|old|<term-old>) [<rev>...]
  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 95a15b918f..a055147f19 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -16,6 +16,7 @@ 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_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"),
@@ -27,7 +28,7 @@ static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --bisect-next-check <good_term> <bad_term> [<term>]"),
 	N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"),
 	N_("git bisect--helper --bisect-start [--term-{old,good}=<term> --term-{new,bad}=<term>]"
-					     "[--no-checkout] [<bad> [<good>...]] [--] [<paths>...]"),
+					    " [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]"),
 	NULL
 };
 
@@ -423,6 +424,7 @@ 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;
@@ -452,6 +454,8 @@ 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++;
@@ -576,6 +580,9 @@ 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 &&
-- 
2.24.3 (Apple Git-128)


  parent reply index

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28 15:44 [PATCH 0/3] Introduce --first-parent flag for git bisect Aaron Lipman via GitGitGadget
2020-07-28 15:44 ` [PATCH 1/3] rev-list: allow bisect and first-parent flags Aaron Lipman via GitGitGadget
2020-07-28 20:23   ` Junio C Hamano
2020-07-28 21:53     ` Junio C Hamano
2020-07-28 15:44 ` [PATCH 2/3] bisect: introduce first-parent flag Aaron Lipman via GitGitGadget
2020-07-28 15:44 ` [PATCH 3/3] bisect: combine args passed to find_bisection() Aaron Lipman via GitGitGadget
2020-07-30  0:27 ` [PATCH v2 0/3] Introduce --first-parent flag for git bisect Aaron Lipman
2020-07-30  0:27   ` [PATCH v2 1/3] rev-list: allow bisect and first-parent flags Aaron Lipman
2020-07-30  0:27   ` [PATCH v2 2/3] bisect: introduce first-parent flag Aaron Lipman
2020-07-30  4:17     ` Junio C Hamano
2020-07-30  0:27   ` [PATCH v2 3/3] bisect: combine args passed to find_bisection() Aaron Lipman
2020-07-30  4:32     ` Junio C Hamano
2020-07-30  0:48   ` [PATCH v2 0/3] Introduce --first-parent flag for git bisect Junio C Hamano
2020-08-01 17:58   ` [PATCH v3 0/4] " Aaron Lipman
2020-08-01 17:58     ` [PATCH v3 1/4] rev-list: allow bisect and first-parent flags Aaron Lipman
2020-08-01 17:58     ` [PATCH v3 2/4] bisect: introduce first-parent flag Aaron Lipman
2020-08-01 17:58     ` [PATCH v3 3/4] bisect: combine args passed to find_bisection() Aaron Lipman
2020-08-01 19:30       ` Martin Ågren
2020-08-01 17:58     ` [PATCH v3 4/4] bisect: consistent style for git bisect run tests Aaron Lipman
2020-08-01 19:27       ` Martin Ågren
2020-08-01 19:06     ` [PATCH v3 0/4] Introduce --first-parent flag for git bisect Junio C Hamano
2020-08-04 22:01     ` [PATCH v4 0/5] " Aaron Lipman
2020-08-04 22:01       ` [PATCH v4 1/5] t6030: modernize "git bisect run" tests Aaron Lipman
2020-08-05  6:11         ` Christian Couder
2020-08-04 22:01       ` [PATCH v4 2/5] rev-list: allow bisect and first-parent flags Aaron Lipman
2020-08-05  0:38         ` Eric Sunshine
2020-08-04 22:01       ` [PATCH v4 3/5] cmd_bisect__helper: defer parsing no-checkout flag Aaron Lipman
2020-08-04 22:01       ` Aaron Lipman [this message]
2020-08-04 22:01       ` [PATCH v4 5/5] bisect: combine args passed to find_bisection() Aaron Lipman
2020-08-04 22:19       ` [PATCH v4 0/5] Introduce --first-parent flag for git bisect Junio C Hamano
2020-08-05  5:55       ` Christian Couder
2020-08-07 21:05         ` Junio C Hamano
2020-08-07 21:17           ` Eric Sunshine
2020-08-07 22:07             ` Junio C Hamano
2020-08-07 22:20               ` Eric Sunshine
2020-08-05  6:18       ` Martin Ågren
2020-08-07 21:58       ` [PATCH v5 " Aaron Lipman
2020-08-07 21:58         ` [PATCH v5 1/5] t6030: modernize "git bisect run" tests Aaron Lipman
2020-08-07 21:58         ` [PATCH v5 2/5] rev-list: allow bisect and first-parent flags Aaron Lipman
2020-08-07 21:58         ` [PATCH v5 3/5] cmd_bisect__helper: defer parsing no-checkout flag Aaron Lipman
2020-08-07 21:58         ` [PATCH v5 4/5] bisect: introduce first-parent flag Aaron Lipman
2020-08-07 21:58         ` [PATCH v5 5/5] bisect: combine args passed to find_bisection() Aaron Lipman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200804220113.5909-5-alipman88@gmail.com \
    --to=alipman88@gmail.com \
    --cc=git@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Git Mailing List Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/git/0 git/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 git git/ https://lore.kernel.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.git


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git