Merge branch 'ds/maintenance-part-3'

Parts of "git maintenance" to ease writing crontab entries (and
other scheduling system configuration) for it.

* ds/maintenance-part-3:
  maintenance: add troubleshooting guide to docs
  maintenance: use 'incremental' strategy by default
  maintenance: create maintenance.strategy config
  maintenance: add start/stop subcommands
  maintenance: add [un]register subcommands
  for-each-repo: run subcommands on configured repos
  maintenance: add --schedule option and config
  maintenance: optionally skip --auto process

6 files changed, 232 insertions, 1 deletions

diff --git a/t/helper/test-crontab.c b/t/helper/test-crontab.c
new file mode 100644
index 0000000000..e7c0137a47
--- /dev/null
+++ b/t/helper/test-crontab.c
@@ -0,0 +1,35 @@
+#include "test-tool.h"
+#include "cache.h"
+
+/*
+ * Usage: test-tool cron <file> [-l]
+ *
+ * If -l is specified, then write the contents of <file> to stdout.
+ * Otherwise, write from stdin into <file>.
+ */
+int cmd__crontab(int argc, const char **argv)
+{
+	int a;
+	FILE *from, *to;
+
+	if (argc == 3 && !strcmp(argv[2], "-l")) {
+		from = fopen(argv[1], "r");
+		if (!from)
+			return 0;
+		to = stdout;
+	} else if (argc == 2) {
+		from = stdin;
+		to = fopen(argv[1], "w");
+	} else
+		return error("unknown arguments");
+
+	while ((a = fgetc(from)) != EOF)
+		fputc(a, to);
+
+	if (argc == 3)
+		fclose(from);
+	else
+		fclose(to);
+
+	return 0;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index a0d3966b29..cab19a9eb5 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -18,6 +18,7 @@ static struct test_cmd cmds[] = {
 	{ "bloom", cmd__bloom },
 	{ "chmtime", cmd__chmtime },
 	{ "config", cmd__config },
+	{ "crontab", cmd__crontab },
 	{ "ctype", cmd__ctype },
 	{ "date", cmd__date },
 	{ "delta", cmd__delta },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 07034d3f38..1467f003af 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -8,6 +8,7 @@ int cmd__advise_if_enabled(int argc, const char **argv);
 int cmd__bloom(int argc, const char **argv);
 int cmd__chmtime(int argc, const char **argv);
 int cmd__config(int argc, const char **argv);
+int cmd__crontab(int argc, const char **argv);
 int cmd__ctype(int argc, const char **argv);
 int cmd__date(int argc, const char **argv);
 int cmd__delta(int argc, const char **argv);
diff --git a/t/t0068-for-each-repo.sh b/t/t0068-for-each-repo.sh
new file mode 100755
index 0000000000..136b4ec839
--- /dev/null
+++ b/t/t0068-for-each-repo.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+test_description='git for-each-repo builtin'
+
+. ./test-lib.sh
+
+test_expect_success 'run based on configured value' '
+	git init one &&
+	git init two &&
+	git init three &&
+	git -C two commit --allow-empty -m "DID NOT RUN" &&
+	git config run.key "$TRASH_DIRECTORY/one" &&
+	git config --add run.key "$TRASH_DIRECTORY/three" &&
+	git for-each-repo --config=run.key commit --allow-empty -m "ran" &&
+	git -C one log -1 --pretty=format:%s >message &&
+	grep ran message &&
+	git -C two log -1 --pretty=format:%s >message &&
+	! grep ran message &&
+	git -C three log -1 --pretty=format:%s >message &&
+	grep ran message &&
+	git for-each-repo --config=run.key -- commit --allow-empty -m "ran again" &&
+	git -C one log -1 --pretty=format:%s >message &&
+	grep again message &&
+	git -C two log -1 --pretty=format:%s >message &&
+	! grep again message &&
+	git -C three log -1 --pretty=format:%s >message &&
+	grep again message
+'
+
+test_done
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index b2def8bb16..d9e68bb2bf 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -9,7 +9,7 @@ GIT_TEST_MULTI_PACK_INDEX=0
 
 test_expect_success 'help text' '
 	test_expect_code 129 git maintenance -h 2>err &&
-	test_i18ngrep "usage: git maintenance run" err &&
+	test_i18ngrep "usage: git maintenance <subcommand>" err &&
 	test_expect_code 128 git maintenance barf 2>err &&
 	test_i18ngrep "invalid subcommand: barf" err &&
 	test_expect_code 129 git maintenance 2>err &&
@@ -28,6 +28,19 @@ test_expect_success 'run [--auto|--quiet]' '
 	test_subcommand git gc --no-quiet <run-no-quiet.txt
 '
 
+test_expect_success 'maintenance.auto config option' '
+	GIT_TRACE2_EVENT="$(pwd)/default" git commit --quiet --allow-empty -m 1 &&
+	test_subcommand git maintenance run --auto --quiet <default &&
+	GIT_TRACE2_EVENT="$(pwd)/true" \
+		git -c maintenance.auto=true \
+		commit --quiet --allow-empty -m 2 &&
+	test_subcommand git maintenance run --auto --quiet  <true &&
+	GIT_TRACE2_EVENT="$(pwd)/false" \
+		git -c maintenance.auto=false \
+		commit --quiet --allow-empty -m 3 &&
+	test_subcommand ! git maintenance run --auto --quiet  <false
+'
+
 test_expect_success 'maintenance.<task>.enabled' '
 	git config maintenance.gc.enabled false &&
 	git config maintenance.commit-graph.enabled true &&
@@ -284,4 +297,148 @@ test_expect_success 'maintenance.incremental-repack.auto' '
 	test_subcommand git multi-pack-index write --no-progress <trace-B
 '
 
+test_expect_success '--auto and --schedule incompatible' '
+	test_must_fail git maintenance run --auto --schedule=daily 2>err &&
+	test_i18ngrep "at most one" err
+'
+
+test_expect_success 'invalid --schedule value' '
+	test_must_fail git maintenance run --schedule=annually 2>err &&
+	test_i18ngrep "unrecognized --schedule" err
+'
+
+test_expect_success '--schedule inheritance weekly -> daily -> hourly' '
+	git config maintenance.loose-objects.enabled true &&
+	git config maintenance.loose-objects.schedule hourly &&
+	git config maintenance.commit-graph.enabled true &&
+	git config maintenance.commit-graph.schedule daily &&
+	git config maintenance.incremental-repack.enabled true &&
+	git config maintenance.incremental-repack.schedule weekly &&
+
+	GIT_TRACE2_EVENT="$(pwd)/hourly.txt" \
+		git maintenance run --schedule=hourly 2>/dev/null &&
+	test_subcommand git prune-packed --quiet <hourly.txt &&
+	test_subcommand ! git commit-graph write --split --reachable \
+		--no-progress <hourly.txt &&
+	test_subcommand ! git multi-pack-index write --no-progress <hourly.txt &&
+
+	GIT_TRACE2_EVENT="$(pwd)/daily.txt" \
+		git maintenance run --schedule=daily 2>/dev/null &&
+	test_subcommand git prune-packed --quiet <daily.txt &&
+	test_subcommand git commit-graph write --split --reachable \
+		--no-progress <daily.txt &&
+	test_subcommand ! git multi-pack-index write --no-progress <daily.txt &&
+
+	GIT_TRACE2_EVENT="$(pwd)/weekly.txt" \
+		git maintenance run --schedule=weekly 2>/dev/null &&
+	test_subcommand git prune-packed --quiet <weekly.txt &&
+	test_subcommand git commit-graph write --split --reachable \
+		--no-progress <weekly.txt &&
+	test_subcommand git multi-pack-index write --no-progress <weekly.txt
+'
+
+test_expect_success 'maintenance.strategy inheritance' '
+	for task in commit-graph loose-objects incremental-repack
+	do
+		git config --unset maintenance.$task.schedule || return 1
+	done &&
+
+	test_when_finished git config --unset maintenance.strategy &&
+	git config maintenance.strategy incremental &&
+
+	GIT_TRACE2_EVENT="$(pwd)/incremental-hourly.txt" \
+		git maintenance run --schedule=hourly --quiet &&
+	GIT_TRACE2_EVENT="$(pwd)/incremental-daily.txt" \
+		git maintenance run --schedule=daily --quiet &&
+
+	test_subcommand git commit-graph write --split --reachable \
+		--no-progress <incremental-hourly.txt &&
+	test_subcommand ! git prune-packed --quiet <incremental-hourly.txt &&
+	test_subcommand ! git multi-pack-index write --no-progress \
+		<incremental-hourly.txt &&
+
+	test_subcommand git commit-graph write --split --reachable \
+		--no-progress <incremental-daily.txt &&
+	test_subcommand git prune-packed --quiet <incremental-daily.txt &&
+	test_subcommand git multi-pack-index write --no-progress \
+		<incremental-daily.txt &&
+
+	# Modify defaults
+	git config maintenance.commit-graph.schedule daily &&
+	git config maintenance.loose-objects.schedule hourly &&
+	git config maintenance.incremental-repack.enabled false &&
+
+	GIT_TRACE2_EVENT="$(pwd)/modified-hourly.txt" \
+		git maintenance run --schedule=hourly --quiet &&
+	GIT_TRACE2_EVENT="$(pwd)/modified-daily.txt" \
+		git maintenance run --schedule=daily --quiet &&
+
+	test_subcommand ! git commit-graph write --split --reachable \
+		--no-progress <modified-hourly.txt &&
+	test_subcommand git prune-packed --quiet <modified-hourly.txt &&
+	test_subcommand ! git multi-pack-index write --no-progress \
+		<modified-hourly.txt &&
+
+	test_subcommand git commit-graph write --split --reachable \
+		--no-progress <modified-daily.txt &&
+	test_subcommand git prune-packed --quiet <modified-daily.txt &&
+	test_subcommand ! git multi-pack-index write --no-progress \
+		<modified-daily.txt
+'
+
+test_expect_success 'register and unregister' '
+	test_when_finished git config --global --unset-all maintenance.repo &&
+	git config --global --add maintenance.repo /existing1 &&
+	git config --global --add maintenance.repo /existing2 &&
+	git config --global --get-all maintenance.repo >before &&
+
+	git maintenance register &&
+	test_cmp_config false maintenance.auto &&
+	git config --global --get-all maintenance.repo >between &&
+	cp before expect &&
+	pwd >>expect &&
+	test_cmp expect between &&
+
+	git maintenance unregister &&
+	git config --global --get-all maintenance.repo >actual &&
+	test_cmp before actual
+'
+
+test_expect_success 'start from empty cron table' '
+	GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance start &&
+
+	# start registers the repo
+	git config --get --global maintenance.repo "$(pwd)" &&
+
+	grep "for-each-repo --config=maintenance.repo maintenance run --schedule=daily" cron.txt &&
+	grep "for-each-repo --config=maintenance.repo maintenance run --schedule=hourly" cron.txt &&
+	grep "for-each-repo --config=maintenance.repo maintenance run --schedule=weekly" cron.txt
+'
+
+test_expect_success 'stop from existing schedule' '
+	GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance stop &&
+
+	# stop does not unregister the repo
+	git config --get --global maintenance.repo "$(pwd)" &&
+
+	# Operation is idempotent
+	GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance stop &&
+	test_must_be_empty cron.txt
+'
+
+test_expect_success 'start preserves existing schedule' '
+	echo "Important information!" >cron.txt &&
+	GIT_TEST_CRONTAB="test-tool crontab cron.txt" git maintenance start &&
+	grep "Important information!" cron.txt
+'
+
+test_expect_success 'register preserves existing strategy' '
+	git config maintenance.strategy none &&
+	git maintenance register &&
+	test_config maintenance.strategy none &&
+	git config --unset maintenance.strategy &&
+	git maintenance register &&
+	test_config maintenance.strategy incremental
+'
+
 test_done
diff --git a/t/test-lib.sh b/t/test-lib.sh
index fa347ed3e1..a863ccee7e 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -1711,6 +1711,7 @@ test_lazy_prereq SHA1 '
 test_lazy_prereq REBASE_P '
 	test -z "$GIT_TEST_SKIP_REBASE_P"
 '
+
 # Special-purpose prereq for transitioning to a new default branch name:
 # Some tests need more than just a mindless (case-preserving) s/master/main/g
 # replacement. The non-trivial adjustments are guarded behind this
@@ -1718,3 +1719,9 @@ test_lazy_prereq REBASE_P '
 test_lazy_prereq PREPARE_FOR_MAIN_BRANCH '
 	test "$GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME" = main
 '
+
+# Ensure that no test accidentally triggers a Git command
+# that runs 'crontab', affecting a user's cron schedule.
+# Tests that verify the cron integration must set this locally
+# to avoid errors.
+GIT_TEST_CRONTAB="exit 1"