[PATCH 0/3] bisect: add --auto-reset to leave when done

[PATCH 0/3] bisect: add --auto-reset to leave when done

[Harald Nordgren via GitGitGadget]

Add a --auto-reset option to git bisect start and git bisect run that
returns to the commit checked out before git bisect start as soon as the
first bad commit is reported, instead of leaving the session active until
git bisect reset is run by hand.

Harald Nordgren (3):
  bisect: read run output from the open descriptor
  bisect: let bisect_reset() optionally check out quietly
  bisect: add --auto-reset to leave when done

 Documentation/git-bisect.adoc | 12 +++++++--
 bisect.c                      |  2 ++
 builtin/bisect.c              | 51 ++++++++++++++++++++++-------------
 t/t6030-bisect-porcelain.sh   | 34 +++++++++++++++++++++++
 4 files changed, 78 insertions(+), 21 deletions(-)


base-commit: f60db8d575adb79761d363e026fb49bddf330c73
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2335%2FHaraldNordgren%2Fbisect-auto-reset-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2335/HaraldNordgren/bisect-auto-reset-v1
Pull-Request: https://github.com/git/git/pull/2335
-- 
gitgitgadget

[PATCH 1/3] bisect: read run output from the open descriptor

[Harald Nordgren via GitGitGadget]

From: Harald Nordgren <haraldnordgren@gmail.com>

"git bisect run" redirects each step's output into BISECT_RUN, then
prints it back by reopening the file by name. Read it from the already
open descriptor instead; this behaves the same and no longer needs the
file to be reachable by name.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
---
 builtin/bisect.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/builtin/bisect.c b/builtin/bisect.c
index 798e28f501..69ea14b1b6 100644
--- a/builtin/bisect.c
+++ b/builtin/bisect.c
@@ -178,17 +178,13 @@ static int append_to_file(const char *path, const char *format, ...)
 	return res;
 }
 
-static int print_file_to_stdout(const char *path)
+static int print_fd_to_stdout(int fd)
 {
-	int fd = open(path, O_RDONLY);
-	int ret = 0;
-
-	if (fd < 0)
-		return error_errno(_("cannot open file '%s' for reading"), path);
+	if (lseek(fd, 0, SEEK_SET) < 0)
+		return error_errno(_("failed to rewind BISECT_RUN output"));
 	if (copy_fd(fd, 1) < 0)
-		ret = error_errno(_("failed to read '%s'"), path);
-	close(fd);
-	return ret;
+		return error_errno(_("failed to read BISECT_RUN output"));
+	return 0;
 }
 
 static int check_term_format(const char *term, const char *orig_term)
@@ -1291,7 +1287,7 @@ static int bisect_run(struct bisect_terms *terms, int argc, const char **argv)
 		else
 			new_state = terms->term_bad;
 
-		temporary_stdout_fd = open(git_path_bisect_run(), O_CREAT | O_WRONLY | O_TRUNC, 0666);
+		temporary_stdout_fd = open(git_path_bisect_run(), O_CREAT | O_RDWR | O_TRUNC, 0666);
 
 		if (temporary_stdout_fd < 0) {
 			res = error_errno(_("cannot open file '%s' for writing"), git_path_bisect_run());
@@ -1307,9 +1303,9 @@ static int bisect_run(struct bisect_terms *terms, int argc, const char **argv)
 		fflush(stdout);
 		dup2(saved_stdout, 1);
 		close(saved_stdout);
-		close(temporary_stdout_fd);
 
-		print_file_to_stdout(git_path_bisect_run());
+		print_fd_to_stdout(temporary_stdout_fd);
+		close(temporary_stdout_fd);
 
 		if (res == BISECT_ONLY_SKIPPED_LEFT)
 			error(_("bisect run cannot continue any more"));
-- 
gitgitgadget

[PATCH 2/3] bisect: let bisect_reset() optionally check out quietly

[Harald Nordgren via GitGitGadget]

From: Harald Nordgren <haraldnordgren@gmail.com>

Add a "quiet" parameter to bisect_reset() that passes "--quiet" to the
checkout restoring the original HEAD, suppressing its progress and
branch-status output.

No caller sets the flag yet, so behavior is unchanged.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
---
 builtin/bisect.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/builtin/bisect.c b/builtin/bisect.c
index 69ea14b1b6..27d30b549e 100644
--- a/builtin/bisect.c
+++ b/builtin/bisect.c
@@ -230,7 +230,7 @@ static int write_terms(const char *bad, const char *good)
 	return res;
 }
 
-static int bisect_reset(const char *commit)
+static int bisect_reset(const char *commit, int quiet)
 {
 	struct strbuf branch = STRBUF_INIT;
 
@@ -251,8 +251,10 @@ static int bisect_reset(const char *commit)
 		struct child_process cmd = CHILD_PROCESS_INIT;
 
 		cmd.git_cmd = 1;
-		strvec_pushl(&cmd.args, "checkout", "--ignore-other-worktrees",
-				branch.buf, "--", NULL);
+		strvec_pushl(&cmd.args, "checkout", "--ignore-other-worktrees", NULL);
+		if (quiet)
+			strvec_push(&cmd.args, "--quiet");
+		strvec_pushl(&cmd.args, branch.buf, "--", NULL);
 		if (run_command(&cmd)) {
 			error(_("could not check out original"
 				" HEAD '%s'. Try 'git bisect"
@@ -1085,7 +1087,7 @@ static enum bisect_error bisect_replay(struct bisect_terms *terms, const char *f
 	if (is_empty_or_missing_file(filename))
 		return error(_("cannot read file '%s' for replaying"), filename);
 
-	if (bisect_reset(NULL))
+	if (bisect_reset(NULL, 0))
 		return BISECT_FAILED;
 
 	fp = fopen(filename, "r");
@@ -1334,7 +1336,7 @@ static int cmd_bisect__reset(int argc, const char **argv, const char *prefix UNU
 	if (argc > 1)
 		return error(_("'%s' requires either no argument or a commit"),
 			     "git bisect reset");
-	return bisect_reset(argc ? argv[0] : NULL);
+	return bisect_reset(argc ? argv[0] : NULL, 0);
 }
 
 static int cmd_bisect__terms(int argc, const char **argv, const char *prefix UNUSED,
-- 
gitgitgadget

[PATCH 3/3] bisect: add --auto-reset to leave when done

[Harald Nordgren via GitGitGadget]

From: Harald Nordgren <haraldnordgren@gmail.com>

When a bisection finished, "git bisect" reported the first bad commit
but left the session active until "git bisect reset" was run by hand.

Add an "--auto-reset" option, accepted by both "git bisect start" and
"git bisect run", that resets as soon as the first bad commit is found,
returning to the commit checked out before "git bisect start". The flag
is persisted in a BISECT_AUTO_RESET state file and the restoring
checkout is done quietly.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
---
 Documentation/git-bisect.adoc | 12 ++++++++++--
 bisect.c                      |  2 ++
 builtin/bisect.c              | 19 +++++++++++++++++--
 t/t6030-bisect-porcelain.sh   | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-bisect.adoc b/Documentation/git-bisect.adoc
index d2115b2990..1b03dbba7a 100644
--- a/Documentation/git-bisect.adoc
+++ b/Documentation/git-bisect.adoc
@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [synopsis]
 git bisect start [--term-(bad|new)=<term-new> --term-(good|old)=<term-old>]
-		 [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<pathspec>...]
+		 [--no-checkout] [--first-parent] [--auto-reset] [<bad> [<good>...]] [--] [<pathspec>...]
 git bisect (bad|new|<term-new>) [<rev>]
 git bisect (good|old|<term-old>) [<rev>...]
 git bisect terms [--term-(good|old) | --term-(bad|new)]
@@ -20,7 +20,7 @@ git bisect reset [<commit>]
 git bisect (visualize|view)
 git bisect replay <logfile>
 git bisect log
-git bisect run <cmd> [<arg>...]
+git bisect run [--auto-reset] <cmd> [<arg>...]
 git bisect help
 
 DESCRIPTION
@@ -385,6 +385,14 @@ 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.
 
+`--auto-reset`::
+	Once the first bad commit is found, clean up the bisection state and
+	return to the commit that was checked out before `git bisect start`,
+	as if `git bisect reset` had been run. The first bad commit is still
+	reported before resetting.
++
+This option may be given to `git bisect start` or to `git bisect run`.
+
 EXAMPLES
 --------
 
diff --git a/bisect.c b/bisect.c
index 94c7028d2a..a34309dd35 100644
--- a/bisect.c
+++ b/bisect.c
@@ -488,6 +488,7 @@ 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_bisect_terms, "BISECT_TERMS")
 static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
+static GIT_PATH_FUNC(git_path_bisect_auto_reset, "BISECT_AUTO_RESET")
 
 static void read_bisect_paths(struct strvec *array)
 {
@@ -1211,6 +1212,7 @@ int bisect_clean_state(void)
 	unlink_or_warn(git_path_bisect_run());
 	unlink_or_warn(git_path_bisect_terms());
 	unlink_or_warn(git_path_bisect_first_parent());
+	unlink_or_warn(git_path_bisect_auto_reset());
 	/*
 	 * Cleanup BISECT_START last to support the --no-checkout option
 	 * introduced in the commit 4796e823a.
diff --git a/builtin/bisect.c b/builtin/bisect.c
index 27d30b549e..b80eccb635 100644
--- a/builtin/bisect.c
+++ b/builtin/bisect.c
@@ -24,11 +24,12 @@ 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_names, "BISECT_NAMES")
 static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
+static GIT_PATH_FUNC(git_path_bisect_auto_reset, "BISECT_AUTO_RESET")
 static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
 
 #define BUILTIN_GIT_BISECT_START_USAGE \
 	N_("git bisect start [--term-(bad|new)=<term-new> --term-(good|old)=<term-old>]\n" \
-	   "                 [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<pathspec>...]")
+	   "                 [--no-checkout] [--first-parent] [--auto-reset] [<bad> [<good>...]] [--] [<pathspec>...]")
 #define BUILTIN_GIT_BISECT_BAD_USAGE \
 	N_("git bisect (bad|new|<term-new>) [<rev>]")
 #define BUILTIN_GIT_BISECT_GOOD_USAGE \
@@ -48,7 +49,7 @@ static GIT_PATH_FUNC(git_path_bisect_run, "BISECT_RUN")
 #define BUILTIN_GIT_BISECT_LOG_USAGE \
 	"git bisect log"
 #define BUILTIN_GIT_BISECT_RUN_USAGE \
-	N_("git bisect run <cmd> [<arg>...]")
+	N_("git bisect run [--auto-reset] <cmd> [<arg>...]")
 #define BUILTIN_GIT_BISECT_HELP_USAGE \
 	"git bisect help"
 
@@ -688,6 +689,8 @@ static enum bisect_error bisect_next(struct bisect_terms *terms, const char *pre
 
 	if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
 		res = bisect_successful(terms);
+		if (!res && !is_empty_or_missing_file(git_path_bisect_auto_reset()))
+			res = bisect_reset(NULL, 1);
 		return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
 	} else if (res == BISECT_ONLY_SKIPPED_LEFT) {
 		res = bisect_skipped_commits(terms);
@@ -711,6 +714,7 @@ static enum bisect_error bisect_start(struct bisect_terms *terms, int argc,
 {
 	int no_checkout = 0;
 	int first_parent_only = 0;
+	int auto_reset = 0;
 	int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 	int flags, pathspec_pos;
 	enum bisect_error res = BISECT_OK;
@@ -743,6 +747,8 @@ static enum bisect_error bisect_start(struct bisect_terms *terms, int argc,
 			no_checkout = 1;
 		} else if (!strcmp(arg, "--first-parent")) {
 			first_parent_only = 1;
+		} else if (!strcmp(arg, "--auto-reset")) {
+			auto_reset = 1;
 		} else if (!strcmp(arg, "--term-good") ||
 			 !strcmp(arg, "--term-old")) {
 			i++;
@@ -857,6 +863,9 @@ static enum bisect_error bisect_start(struct bisect_terms *terms, int argc,
 	if (first_parent_only)
 		write_file(git_path_bisect_first_parent(), "\n");
 
+	if (auto_reset)
+		write_file(git_path_bisect_auto_reset(), "\n");
+
 	if (no_checkout) {
 		if (repo_get_oid(the_repository, start_head.buf, &oid) < 0) {
 			res = error(_("invalid ref: '%s'"), start_head.buf);
@@ -1242,6 +1251,12 @@ static int bisect_run(struct bisect_terms *terms, int argc, const char **argv)
 	if (bisect_next_check(terms, NULL))
 		return BISECT_FAILED;
 
+	if (argc && !strcmp(argv[0], "--auto-reset")) {
+		write_file(git_path_bisect_auto_reset(), "\n");
+		argc--;
+		argv++;
+	}
+
 	if (!argc) {
 		error(_("bisect run failed: no command provided."));
 		return BISECT_FAILED;
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index 081116220a..5389ba388c 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -453,6 +453,40 @@ test_expect_success '"git bisect run" simple case' '
 	git bisect reset
 '
 
+test_expect_success '"git bisect start --auto-reset" leaves the bisection' '
+	test_when_finished "git bisect reset" &&
+	git bisect start --auto-reset $HASH4 $HASH2 &&
+	git bisect bad &&
+	test_path_is_missing "$(git rev-parse --git-path BISECT_START)"
+'
+
+test_expect_success '"git bisect run --auto-reset" leaves the bisection' '
+	test_when_finished "git bisect reset" &&
+	write_script test_script.sh <<-\EOF &&
+	! grep Another hello >/dev/null
+	EOF
+	git bisect start $HASH4 $HASH2 &&
+	git bisect run --auto-reset ./test_script.sh >my_bisect_log.txt &&
+	grep "$HASH3 is the first .bad. commit" my_bisect_log.txt &&
+	test_path_is_missing "$(git rev-parse --git-path BISECT_START)"
+'
+
+test_expect_success 'without --auto-reset the bisection state is kept' '
+	test_when_finished "git bisect reset" &&
+	git bisect start $HASH4 $HASH2 &&
+	git bisect bad &&
+	test_path_is_file "$(git rev-parse --git-path BISECT_START)"
+'
+
+test_expect_success '--auto-reset does not leak into a later bisection' '
+	test_when_finished "git bisect reset" &&
+	git bisect start --auto-reset $HASH4 $HASH2 &&
+	git bisect bad &&
+	git bisect start $HASH4 $HASH2 &&
+	git bisect bad &&
+	test_path_is_file "$(git rev-parse --git-path BISECT_START)"
+'
+
 # We want to automatically find the commit that
 # added "Ciao" into hello.
 test_expect_success '"git bisect run" with more complex "git bisect start"' '
-- 
gitgitgadget