[PATCH] describe: enable sparse index for describe

[PATCH] describe: enable sparse index for describe

[Raghul Nanth A via GitGitGadget]

From: Raghul Nanth A <nanth.raghul@gmail.com>

Add usage and performance tests for describe

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---
    describe: enable sparse index for describe

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1480%2FNanthR%2Fdescribe-sparse-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1480/NanthR/describe-sparse-v1
Pull-Request: https://github.com/git/git/pull/1480

 builtin/describe.c                       |   2 +
 t/perf/p2000-sparse-operations.sh        |  14 +-
 t/t1092-sparse-checkout-compatibility.sh |  10 +
 t/t6121-describe-sparse.sh               | 675 +++++++++++++++++++++++
 4 files changed, 697 insertions(+), 4 deletions(-)
 create mode 100755 t/t6121-describe-sparse.sh

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8c..7ff9b5e4b20 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a0..a8a9ed79441 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -59,7 +59,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 3 &&
 		git update-index --index-version=3 &&
-		git checkout HEAD~4
+		git checkout HEAD~4 &&
+		git tag -a v1.0 -m "Final"
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v4 &&
 	(
@@ -68,7 +69,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 4 &&
 		git update-index --index-version=4 &&
-		git checkout HEAD~4
+		git checkout HEAD~4 &&
+		git tag -a v1.0 -m "Final"
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v3 &&
 	(
@@ -77,7 +79,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 3 &&
 		git update-index --index-version=3 &&
-		git checkout HEAD~4
+		git checkout HEAD~4 &&
+		git tag -a v1.0 -m "Final"
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v4 &&
 	(
@@ -86,7 +89,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 4 &&
 		git update-index --index-version=4 &&
-		git checkout HEAD~4
+		git checkout HEAD~4 &&
+		git tag -a v1.0 -m "Final"
 	)
 '
 
@@ -125,5 +129,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >> new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e1..dea6f50ca84 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,16 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+	ensure_not_expanded tag -a v1.0 -m "Version 1" &&
+	ensure_not_expanded describe --dirty &&
+	ensure_not_expanded describe &&
+	echo "test" >> sparse-index/extra.txt &&
+	ensure_not_expanded describe --dirty &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
diff --git a/t/t6121-describe-sparse.sh b/t/t6121-describe-sparse.sh
new file mode 100755
index 00000000000..1eebcdb55dd
--- /dev/null
+++ b/t/t6121-describe-sparse.sh
@@ -0,0 +1,675 @@
+#!/bin/sh
+
+test_description='git describe in sparse checked out trees'
+
+#  o---o-----o----o----o-------o----x
+#       \   D,R   e           /
+#        \---o-------------o-'
+#         \  B            /
+#          `-o----o----o-'
+#                 A    c
+#
+# First parent of a merge commit is on the same line, second parent below.
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+check_describe () {
+	indir= &&
+	while test $# != 0
+	do
+		case "$1" in
+		-C)
+			indir="$2"
+			shift
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done &&
+	indir=${indir:+"$indir"/} &&
+	expect="$1"
+	shift
+	describe_opts="$@"
+	test_expect_success "describe $describe_opts" '
+		git ${indir:+ -C "$indir"} describe $describe_opts >raw &&
+		sed -e "s/-g[0-9a-f]*\$/-gHASH/" <raw >actual &&
+		echo "$expect" >expect &&
+		test_cmp expect actual
+	'
+}
+
+test_expect_success setup '
+	test_commit initial file one &&
+	test_commit second file two &&
+	test_commit third file three &&
+	test_commit --annotate A file A &&
+	test_commit c file c &&
+
+	git reset --hard second &&
+	test_commit --annotate B side B &&
+
+	test_tick &&
+	git merge -m Merged c &&
+	merged=$(git rev-parse HEAD) &&
+
+	git reset --hard second &&
+	test_commit --no-tag D another D &&
+
+	test_tick &&
+	git tag -a -m R R &&
+
+	test_commit e another DD &&
+	test_commit --no-tag "yet another" another DDD &&
+
+	test_tick &&
+	git merge -m Merged $merged &&
+
+	test_commit --no-tag x file &&
+	git sparse-checkout init --cone
+'
+
+check_describe A-8-gHASH HEAD
+check_describe A-7-gHASH HEAD^
+check_describe R-2-gHASH HEAD^^
+check_describe A-3-gHASH HEAD^^2
+check_describe B HEAD^^2^
+check_describe R-1-gHASH HEAD^^^
+
+check_describe c-7-gHASH --tags HEAD
+check_describe c-6-gHASH --tags HEAD^
+check_describe e-1-gHASH --tags HEAD^^
+check_describe c-2-gHASH --tags HEAD^^2
+check_describe B --tags HEAD^^2^
+check_describe e --tags HEAD^^^
+
+check_describe heads/main --all HEAD
+check_describe tags/c-6-gHASH --all HEAD^
+check_describe tags/e --all HEAD^^^
+
+check_describe B-0-gHASH --long HEAD^^2^
+check_describe A-3-gHASH --long HEAD^^2
+
+check_describe c-7-gHASH --tags
+check_describe e-3-gHASH --first-parent --tags
+
+test_expect_success 'describe --contains defaults to HEAD without commit-ish' '
+	echo "A^0" >expect &&
+	git checkout A &&
+	test_when_finished "git checkout -" &&
+	git describe --contains >actual &&
+	test_cmp expect actual
+'
+
+check_describe tags/A --all A^0
+
+test_expect_success 'renaming tag A to Q locally produces a warning' "
+	git update-ref refs/tags/Q $(git rev-parse refs/tags/A) &&
+	git update-ref -d refs/tags/A &&
+	git describe HEAD 2>err >out &&
+	cat >expected <<-\EOF &&
+	warning: tag 'Q' is externally known as 'A'
+	EOF
+	test_cmp expected err &&
+	grep -E '^A-8-g[0-9a-f]+$' out
+"
+
+test_expect_success 'misnamed annotated tag forces long output' '
+	description=$(git describe --no-long Q^0) &&
+	expr "$description" : "A-0-g[0-9a-f]*$" &&
+	git rev-parse --verify "$description" >actual &&
+	git rev-parse --verify Q^0 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'abbrev=0 will not break misplaced tag (1)' '
+	description=$(git describe --abbrev=0 Q^0) &&
+	expr "$description" : "A-0-g[0-9a-f]*$"
+'
+
+test_expect_success 'abbrev=0 will not break misplaced tag (2)' '
+	description=$(git describe --abbrev=0 c^0) &&
+	expr "$description" : "A-1-g[0-9a-f]*$"
+'
+
+test_expect_success 'rename tag Q back to A' '
+	git update-ref refs/tags/A $(git rev-parse refs/tags/Q) &&
+	git update-ref -d refs/tags/Q
+'
+
+test_expect_success 'pack tag refs' 'git pack-refs'
+check_describe A-8-gHASH HEAD
+
+test_expect_success 'describe works from outside repo using --git-dir' '
+	git clone --bare "$TRASH_DIRECTORY" "$TRASH_DIRECTORY/bare" &&
+	git --git-dir "$TRASH_DIRECTORY/bare" describe >out &&
+	grep -E "^A-8-g[0-9a-f]+$" out
+'
+
+check_describe "A-8-gHASH" --dirty
+
+test_expect_success 'describe --dirty with --work-tree' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep -E "^A-8-g[0-9a-f]+$" out
+'
+
+test_expect_success 'set-up dirty work tree' '
+	echo >>file
+'
+
+test_expect_success 'describe --dirty with --work-tree (dirty)' '
+	git describe --dirty >expected &&
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep -E "^A-8-g[0-9a-f]+-dirty$" out &&
+	test_cmp expected out
+'
+
+test_expect_success 'describe --dirty=.mod with --work-tree (dirty)' '
+	git describe --dirty=.mod >expected &&
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty=.mod >"$TRASH_DIRECTORY/out"
+	) &&
+	grep -E "^A-8-g[0-9a-f]+.mod$" out &&
+	test_cmp expected out
+'
+
+test_expect_success 'describe --dirty HEAD' '
+	test_must_fail git describe --dirty HEAD
+'
+
+test_expect_success 'set-up matching pattern tests' '
+	git tag -a -m test-annotated test-annotated &&
+	echo >>file &&
+	test_tick &&
+	git commit -a -m "one more" &&
+	git tag test1-lightweight &&
+	echo >>file &&
+	test_tick &&
+	git commit -a -m "yet another" &&
+	git tag test2-lightweight &&
+	echo >>file &&
+	test_tick &&
+	git commit -a -m "even more"
+
+'
+
+check_describe "test-annotated-3-gHASH" --match="test-*"
+
+check_describe "test1-lightweight-2-gHASH" --tags --match="test1-*"
+
+check_describe "test2-lightweight-1-gHASH" --tags --match="test2-*"
+
+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test2-*" HEAD^
+
+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test1-*" --match="test2-*" HEAD^
+
+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test1-*" --no-match --match="test2-*" HEAD^
+
+check_describe "test1-lightweight-2-gHASH" --long --tags --match="test1-*" --match="test3-*" HEAD
+
+check_describe "test1-lightweight-2-gHASH" --long --tags --match="test3-*" --match="test1-*" HEAD
+
+test_expect_success 'set-up branches' '
+	git branch branch_A A &&
+	git branch branch_C c &&
+	git update-ref refs/remotes/origin/remote_branch_A "A^{commit}" &&
+	git update-ref refs/remotes/origin/remote_branch_C "c^{commit}" &&
+	git update-ref refs/original/original_branch_A test-annotated~2
+'
+
+check_describe "heads/branch_A-11-gHASH" --all --match="branch_*" --exclude="branch_C" HEAD
+
+check_describe "remotes/origin/remote_branch_A-11-gHASH" --all --match="origin/remote_branch_*" --exclude="origin/remote_branch_C" HEAD
+
+check_describe "original/original_branch_A-6-gHASH" --all test-annotated~1
+
+test_expect_success '--match does not work for other types' '
+	test_must_fail git describe --all --match="*original_branch_*" test-annotated~1
+'
+
+test_expect_success '--exclude does not work for other types' '
+	R=$(git describe --all --exclude="any_pattern_even_not_matching" test-annotated~1) &&
+	case "$R" in
+	*original_branch_A*) echo "fail: Found unknown reference $R with --exclude"
+		false;;
+	*) echo ok: Found some known type;;
+	esac
+'
+
+test_expect_success 'name-rev with exact tags' '
+	echo A >expect &&
+	tag_object=$(git rev-parse refs/tags/A) &&
+	git name-rev --tags --name-only $tag_object >actual &&
+	test_cmp expect actual &&
+
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	git name-rev --tags --name-only $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'name-rev --all' '
+	>expect.unsorted &&
+	for rev in $(git rev-list --all)
+	do
+		git name-rev $rev >>expect.unsorted || return 1
+	done &&
+	sort <expect.unsorted >expect &&
+	git name-rev --all >actual.unsorted &&
+	sort <actual.unsorted >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'name-rev --annotate-stdin' '
+	>expect.unsorted &&
+	for rev in $(git rev-list --all)
+	do
+		name=$(git name-rev --name-only $rev) &&
+		echo "$rev ($name)" >>expect.unsorted || return 1
+	done &&
+	sort <expect.unsorted >expect &&
+	git rev-list --all | git name-rev --annotate-stdin >actual.unsorted &&
+	sort <actual.unsorted >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'name-rev --stdin deprecated' "
+	git rev-list --all | git name-rev --stdin 2>actual &&
+	grep -E 'warning: --stdin is deprecated' actual
+"
+
+test_expect_success 'describe --contains with the exact tags' '
+	echo "A^0" >expect &&
+	tag_object=$(git rev-parse refs/tags/A) &&
+	git describe --contains $tag_object >actual &&
+	test_cmp expect actual &&
+
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	git describe --contains $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --contains and --match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="B" --match="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --exclude' '
+	echo "c~1" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	test_must_fail git describe --contains --match="B" $tagged_commit &&
+	git describe --contains --match="?" --exclude="A" $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe --contains and --no-match' '
+	echo "A^0" >expect &&
+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
+	git describe --contains --match="B" --no-match $tagged_commit >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'setup and absorb a submodule' '
+	git init sub1 &&
+	test_commit -C sub1 initial &&
+	git sparse-checkout add sub1 &&
+	git submodule add ./sub1 &&
+	git submodule absorbgitdirs &&
+	git commit -a -m "add submodule" &&
+	git describe --dirty >expect &&
+	git describe --broken >out &&
+	test_cmp expect out
+'
+
+test_expect_success 'describe chokes on severely broken submodules' '
+	mv .git/modules/sub1/ .git/modules/sub_moved &&
+	test_must_fail git describe --dirty
+'
+
+test_expect_success 'describe ignoring a broken submodule' '
+	git describe --broken >out &&
+	grep broken out
+'
+
+test_expect_success 'describe with --work-tree ignoring a broken submodule' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --broken >"$TRASH_DIRECTORY/out"
+	) &&
+	test_when_finished "mv .git/modules/sub_moved .git/modules/sub1" &&
+	grep broken out
+'
+
+test_expect_success 'describe a blob at a directly tagged commit' '
+	echo "make it a unique blob" >file &&
+	git add file && git commit -m "content in file" &&
+	git tag -a -m "latest annotated tag" unique-file &&
+	git describe HEAD:file >actual &&
+	echo "unique-file:file" >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe a blob with its first introduction' '
+	git commit --allow-empty -m "empty commit" &&
+	git rm file &&
+	git commit -m "delete blob" &&
+	git revert HEAD &&
+	git commit --allow-empty -m "empty commit" &&
+	git describe HEAD:file >actual &&
+	echo "unique-file:file" >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'describe directly tagged blob' '
+	git tag test-blob unique-file:file &&
+	git describe test-blob >actual &&
+	echo "unique-file:file" >expect &&
+	# suboptimal: we rather want to see "test-blob"
+	test_cmp expect actual
+'
+
+test_expect_success 'describe tag object' '
+	git tag test-blob-1 -a -m msg unique-file:file &&
+	test_must_fail git describe test-blob-1 2>actual &&
+	test_i18ngrep "fatal: test-blob-1 is neither a commit nor blob" actual
+'
+
+test_expect_success ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '
+	i=1 &&
+	while test $i -lt 8000
+	do
+		echo "commit refs/heads/main
+committer A U Thor <author@example.com> $((1000000000 + $i * 100)) +0200
+data <<EOF
+commit #$i
+EOF" &&
+		if test $i = 1
+		then
+			echo "from refs/heads/main^0"
+		fi &&
+		i=$(($i + 1)) || return 1
+	done | git fast-import &&
+	git checkout main &&
+	git tag far-far-away HEAD^ &&
+	echo "HEAD~4000 tags/far-far-away~3999" >expect &&
+	git name-rev HEAD~4000 >actual &&
+	test_cmp expect actual &&
+	run_with_limited_stack git name-rev HEAD~4000 >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success ULIMIT_STACK_SIZE 'describe works in a deep repo' '
+	git tag -f far-far-away HEAD~7999 &&
+	echo "far-far-away" >expect &&
+	git describe --tags --abbrev=0 HEAD~4000 >actual &&
+	test_cmp expect actual &&
+	run_with_limited_stack git describe --tags --abbrev=0 HEAD~4000 >actual &&
+	test_cmp expect actual
+'
+
+check_describe tags/A --all A
+check_describe tags/c --all c
+check_describe heads/branch_A --all --match='branch_*' branch_A
+
+test_expect_success 'describe complains about tree object' '
+	test_must_fail git describe HEAD^{tree}
+'
+
+test_expect_success 'describe complains about missing object' '
+	test_must_fail git describe $ZERO_OID
+'
+
+test_expect_success 'name-rev a rev shortly after epoch' '
+	test_when_finished "git checkout main" &&
+
+	git checkout --orphan no-timestamp-underflow &&
+	# Any date closer to epoch than the CUTOFF_DATE_SLOP constant
+	# in builtin/name-rev.c.
+	GIT_COMMITTER_DATE="@1234 +0000" \
+	git commit -m "committer date shortly after epoch" &&
+	old_commit_oid=$(git rev-parse HEAD) &&
+
+	echo "$old_commit_oid no-timestamp-underflow" >expect &&
+	git name-rev $old_commit_oid >actual &&
+	test_cmp expect actual
+'
+
+# A--------------main
+#  \            /
+#   \----------M2
+#    \        /
+#     \---M1-C
+#      \ /
+#       B
+test_expect_success 'name-rev covers all conditions while looking at parents' '
+	git init repo &&
+	(
+		cd repo &&
+
+		echo A >file &&
+		git add file &&
+		git commit -m A &&
+		A=$(git rev-parse HEAD) &&
+
+		git checkout --detach &&
+		echo B >file &&
+		git commit -m B file &&
+		B=$(git rev-parse HEAD) &&
+
+		git checkout $A &&
+		git merge --no-ff $B &&  # M1
+
+		echo C >file &&
+		git commit -m C file &&
+
+		git checkout $A &&
+		git merge --no-ff HEAD@{1} && # M2
+
+		git checkout main &&
+		git merge --no-ff HEAD@{1} &&
+
+		echo "$B main^2^2~1^2" >expect &&
+		git name-rev $B >actual &&
+
+		test_cmp expect actual &&
+		git sparse-checkout init --cone
+	)
+'
+
+# A-B-C-D-E-main
+#
+# Where C has a non-monotonically increasing commit timestamp w.r.t. other
+# commits
+test_expect_success 'non-monotonic commit dates setup' '
+	UNIX_EPOCH_ZERO="@0 +0000" &&
+	git init non-monotonic &&
+	test_commit -C non-monotonic A &&
+	test_commit -C non-monotonic --no-tag B &&
+	test_commit -C non-monotonic --no-tag --date "$UNIX_EPOCH_ZERO" C &&
+	test_commit -C non-monotonic D &&
+	test_commit -C non-monotonic E &&
+	(
+		cd non-monotonic &&
+		git sparse-checkout init --cone
+	)
+'
+
+test_expect_success 'name-rev with commitGraph handles non-monotonic timestamps' '
+	test_config -C non-monotonic core.commitGraph true &&
+	(
+		cd non-monotonic &&
+
+		git commit-graph write --reachable &&
+
+		echo "main~3 tags/D~2" >expect &&
+		git name-rev --tags main~3 >actual &&
+
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'name-rev --all works with non-monotonic timestamps' '
+	test_config -C non-monotonic core.commitGraph false &&
+	(
+		cd non-monotonic &&
+
+		rm -rf .git/info/commit-graph* &&
+
+		cat >tags <<-\EOF &&
+		tags/E
+		tags/D
+		tags/D~1
+		tags/D~2
+		tags/A
+		EOF
+
+		git log --pretty=%H >revs &&
+
+		paste -d" " revs tags | sort >expect &&
+
+		git name-rev --tags --all | sort >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'name-rev --annotate-stdin works with non-monotonic timestamps' '
+	test_config -C non-monotonic core.commitGraph false &&
+	(
+		cd non-monotonic &&
+
+		rm -rf .git/info/commit-graph* &&
+
+		cat >expect <<-\EOF &&
+		E
+		D
+		D~1
+		D~2
+		A
+		EOF
+
+		git log --pretty=%H >revs &&
+		git name-rev --tags --annotate-stdin --name-only <revs >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'name-rev --all works with commitGraph' '
+	test_config -C non-monotonic core.commitGraph true &&
+	(
+		cd non-monotonic &&
+
+		git commit-graph write --reachable &&
+
+		cat >tags <<-\EOF &&
+		tags/E
+		tags/D
+		tags/D~1
+		tags/D~2
+		tags/A
+		EOF
+
+		git log --pretty=%H >revs &&
+
+		paste -d" " revs tags | sort >expect &&
+
+		git name-rev --tags --all | sort >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'name-rev --annotate-stdin works with commitGraph' '
+	test_config -C non-monotonic core.commitGraph true &&
+	(
+		cd non-monotonic &&
+
+		git commit-graph write --reachable &&
+
+		cat >expect <<-\EOF &&
+		E
+		D
+		D~1
+		D~2
+		A
+		EOF
+
+		git log --pretty=%H >revs &&
+		git name-rev --tags --annotate-stdin --name-only <revs >actual &&
+		test_cmp expect actual
+	)
+'
+
+#               B
+#               o
+#                \
+#  o-----o---o----x
+#        A
+#
+test_expect_success 'setup: describe commits with disjoint bases' '
+	git init disjoint1 &&
+	(
+		cd disjoint1 &&
+
+		echo o >> file && git add file && git commit -m o &&
+		echo A >> file && git add file && git commit -m A &&
+		git tag A -a -m A &&
+		echo o >> file && git add file && git commit -m o &&
+
+		git checkout --orphan branch && rm file &&
+		echo B > file2 && git add file2 && git commit -m B &&
+		git tag B -a -m B &&
+		git merge --no-ff --allow-unrelated-histories main -m x &&
+		git sparse-checkout init --cone
+	)
+'
+
+check_describe -C disjoint1 "A-3-gHASH" HEAD
+
+#           B
+#   o---o---o------------.
+#                         \
+#                  o---o---x
+#                  A
+#
+test_expect_success 'setup: describe commits with disjoint bases 2' '
+	git init disjoint2 &&
+	(
+		cd disjoint2 &&
+
+		echo A >> file && git add file && GIT_COMMITTER_DATE="2020-01-01 18:00" git commit -m A &&
+		git tag A -a -m A &&
+		echo o >> file && git add file && GIT_COMMITTER_DATE="2020-01-01 18:01" git commit -m o &&
+
+		git checkout --orphan branch &&
+		echo o >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:00" git commit -m o &&
+		echo o >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:01" git commit -m o &&
+		echo B >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:02" git commit -m B &&
+		git tag B -a -m B &&
+		git merge --no-ff --allow-unrelated-histories main -m x &&
+		git sparse-checkout init --cone
+	)
+'
+
+check_describe -C disjoint2 "B-3-gHASH" HEAD
+
+test_expect_success 'setup misleading taggerdates' '
+	GIT_COMMITTER_DATE="2006-12-12 12:31" git tag -a -m "another tag" newer-tag-older-commit unique-file~1
+'
+
+check_describe newer-tag-older-commit~1 --contains unique-file~2
+
+test_done

base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e
-- 
gitgitgadget

Re: [PATCH] describe: enable sparse index for describe

[Junio C Hamano]

"Raghul Nanth A via GitGitGadget" <gitgitgadget@gmail.com> writes:

>  builtin/describe.c                       |   2 +
>  t/perf/p2000-sparse-operations.sh        |  14 +-
>  t/t1092-sparse-checkout-compatibility.sh |  10 +
>  t/t6121-describe-sparse.sh               | 675 +++++++++++++++++++++++
>  4 files changed, 697 insertions(+), 4 deletions(-)
>  create mode 100755 t/t6121-describe-sparse.sh

This copying of a file with 600+ lines only to touch up a handful
lines (like a 20+ lines patch) is almost criminal.  Imagine the
effort to keep them in sync over time, when "describe" itself may
learn new features and improved output, independent from the
sparse-index compatibility.

Can't we do better than this with a bit of refactoring?

> diff --git a/builtin/describe.c b/builtin/describe.c
> index 5b5930f5c8c..7ff9b5e4b20 100644
> --- a/builtin/describe.c
> +++ b/builtin/describe.c
> @@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
>  			int fd, result;
>  
>  			setup_work_tree();
> +			prepare_repo_settings(the_repository);
> +			the_repository->settings.command_requires_full_index = 0;

Offhand, the only case I know that "describe" even _needs_ a working
tree or the index is when asked to do the "--dirty" thing.  To
figure out if the working tree files are modified, the code calls
into run_diff_index(), but has that codepath been made sparse-index
aware already?

> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
> index 3242cfe91a0..a8a9ed79441 100755
> --- a/t/perf/p2000-sparse-operations.sh
> +++ b/t/perf/p2000-sparse-operations.sh
> @@ -59,7 +59,8 @@ test_expect_success 'setup repo and indexes' '
>  		git sparse-checkout set $SPARSE_CONE &&
>  		git config index.version 3 &&
>  		git update-index --index-version=3 &&
> -		git checkout HEAD~4
> +		git checkout HEAD~4 &&
> +		git tag -a v1.0 -m "Final"
>  	) &&
>  	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v4 &&
>  	(
> @@ -68,7 +69,8 @@ test_expect_success 'setup repo and indexes' '
>  		git sparse-checkout set $SPARSE_CONE &&
>  		git config index.version 4 &&
>  		git update-index --index-version=4 &&
> -		git checkout HEAD~4
> +		git checkout HEAD~4 &&
> +		git tag -a v1.0 -m "Final"
>  	) &&
>  	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v3 &&
>  	(
> @@ -77,7 +79,8 @@ test_expect_success 'setup repo and indexes' '
>  		git sparse-checkout set $SPARSE_CONE &&
>  		git config index.version 3 &&
>  		git update-index --index-version=3 &&
> -		git checkout HEAD~4
> +		git checkout HEAD~4 &&
> +		git tag -a v1.0 -m "Final"
>  	) &&
>  	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v4 &&
>  	(
> @@ -86,7 +89,8 @@ test_expect_success 'setup repo and indexes' '
>  		git sparse-checkout set $SPARSE_CONE &&
>  		git config index.version 4 &&
>  		git update-index --index-version=4 &&
> -		git checkout HEAD~4
> +		git checkout HEAD~4 &&
> +		git tag -a v1.0 -m "Final"
>  	)
>  '

It is unclear from the proposed commit log what the relevance of
adding a step to create an annotated tag to these tests.  It is not
like any later step uses that tag to figure out anything.  There may
be good reasons to add these tags (otherwise you would not be adding
them to these tests), but please explain why in the proposed log
message so that future readers of the "git log -p" do not have to
ask this question.

> @@ -125,5 +129,7 @@ test_perf_on_all git checkout-index -f --all
>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>  test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
>  test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
> +test_perf_on_all git describe --dirty
> +test_perf_on_all 'echo >> new && git describe --dirty'
>  
>  test_done

Just like '>', '>>' is a rediraction operator and should have SP
before it (you got it right) and no SP between it and its operand.
I.e.

	echo >>new && git describe --dirty

You have the same in t1092, I think.

Re: [PATCH] describe: enable sparse index for describe

[Derrick Stolee]

On 3/27/23 2:26 PM, Junio C Hamano wrote:
> "Raghul Nanth A via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>>  builtin/describe.c                       |   2 +
>>  t/perf/p2000-sparse-operations.sh        |  14 +-
>>  t/t1092-sparse-checkout-compatibility.sh |  10 +
>>  t/t6121-describe-sparse.sh               | 675 +++++++++++++++++++++++
>>  4 files changed, 697 insertions(+), 4 deletions(-)
>>  create mode 100755 t/t6121-describe-sparse.sh
> 
> This copying of a file with 600+ lines only to touch up a handful
> lines (like a 20+ lines patch) is almost criminal.  Imagine the
> effort to keep them in sync over time, when "describe" itself may
> learn new features and improved output, independent from the
> sparse-index compatibility.
> 
> Can't we do better than this with a bit of refactoring?
> 
>> diff --git a/builtin/describe.c b/builtin/describe.c
>> index 5b5930f5c8c..7ff9b5e4b20 100644
>> --- a/builtin/describe.c
>> +++ b/builtin/describe.c
>> @@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
>>  			int fd, result;
>>  
>>  			setup_work_tree();
>> +			prepare_repo_settings(the_repository);
>> +			the_repository->settings.command_requires_full_index = 0;
> 
> Offhand, the only case I know that "describe" even _needs_ a working
> tree or the index is when asked to do the "--dirty" thing.  To
> figure out if the working tree files are modified, the code calls
> into run_diff_index(), but has that codepath been made sparse-index
> aware already?

It seems that this is a case where we can rely on the existing
changes around run_diff_index(), which is nice. We get a very
easy win for a narrow case.

And I agree about the test case situation. It would suffice to
show some checks that the result is the same across all cases
in t1092 for 'git describe --dirty'. Those should be the only
new correctness tests necessary for this change.

>> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh

>> @@ -86,7 +89,8 @@ test_expect_success 'setup repo and indexes' '
>>  		git sparse-checkout set $SPARSE_CONE &&
>>  		git config index.version 4 &&
>>  		git update-index --index-version=4 &&
>> -		git checkout HEAD~4
>> +		git checkout HEAD~4 &&
>> +		git tag -a v1.0 -m "Final"
>>  	)
>>  '
> 
> It is unclear from the proposed commit log what the relevance of
> adding a step to create an annotated tag to these tests.  It is not
> like any later step uses that tag to figure out anything.  There may
> be good reasons to add these tags (otherwise you would not be adding
> them to these tests), but please explain why in the proposed log
> message so that future readers of the "git log -p" do not have to
> ask this question.

I imagine that 'git describe' reports something better when a tag
is reachable from HEAD. Would be good to make that clear.

Indeed, when removing these lines and running the test on a repo
without any tags, the test fails with this message:

  fatal: No names found, cannot describe anything.

These tags could be added earlier in the test, in one step:

diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a0..ba13317c942 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -45,6 +45,7 @@ test_expect_success 'setup repo and indexes' '
 	git sparse-checkout init --cone &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
+	git tag -a v1.0 -m "final" &&
 
 	for l2 in f1 f2 f3 f4
 	do

The tests then run on the four examples cloned from this copy.

>> @@ -125,5 +129,7 @@ test_perf_on_all git checkout-index -f --all
>>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>>  test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
>>  test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
>> +test_perf_on_all git describe --dirty
>> +test_perf_on_all 'echo >> new && git describe --dirty'
>>  
>>  test_done
> 
> Just like '>', '>>' is a rediraction operator and should have SP
> before it (you got it right) and no SP between it and its operand.
> I.e.
> 
> 	echo >>new && git describe --dirty
> 
> You have the same in t1092, I think.

Also, since you are adding these performance tests, it would be
nice to see their results in the commit message. You can get
values without and with this change using (from t/perf/):

GIT_PERF_REPEAT_COUNT=10 ./run HEAD~1 HEAD -- p2000-sparse-operations.sh

For example, I ran this on my machine (after deleting the other tests
so it ran faster) and got these results:

Test                                                      HEAD~1            HEAD                  
--------------------------------------------------------------------------------------------------
2000.2: git describe --dirty (full-v3)                    0.36(0.07+0.32)   0.45(0.08+0.37) +25.0%
2000.3: git describe --dirty (full-v4)                    0.39(0.08+0.32)   0.42(0.08+0.35) +7.7% 
2000.4: git describe --dirty (sparse-v3)                  1.49(0.91+0.58)   0.33(0.04+0.59) -77.9%
2000.5: git describe --dirty (sparse-v4)                  1.48(0.92+0.57)   0.34(0.04+0.60) -77.0%
2000.6: echo >> new && git describe --dirty (full-v3)     0.37(0.07+0.32)   0.44(0.08+0.36) +18.9%
2000.7: echo >> new && git describe --dirty (full-v4)     0.40(0.08+0.32)   0.42(0.08+0.36) +5.0% 
2000.8: echo >> new && git describe --dirty (sparse-v3)   1.59(0.97+0.62)   0.33(0.04+0.57) -79.2%
2000.9: echo >> new && git describe --dirty (sparse-v4)   1.64(0.98+0.64)   0.31(0.03+0.54) -81.1%

Thanks,
-Stolee

Re: [PATCH] describe: enable sparse index for describe

[Junio C Hamano]

Derrick Stolee <derrickstolee@github.com> writes:

>>>  			setup_work_tree();
>>> +			prepare_repo_settings(the_repository);
>>> +			the_repository->settings.command_requires_full_index = 0;
>> 
>> Offhand, the only case I know that "describe" even _needs_ a working
>> tree or the index is when asked to do the "--dirty" thing.  To
>> figure out if the working tree files are modified, the code calls
>> into run_diff_index(), but has that codepath been made sparse-index
>> aware already?
>
> It seems that this is a case where we can rely on the existing
> changes around run_diff_index(), which is nice. We get a very
> easy win for a narrow case.

Hmph, so "diff-index" is already sparse-index aware?  I looked for
any old commit that flips .command_requires_full_index to false for
the command and didn't find it, and if I recall correctly (I only
checked when I wrote the comment you are responding to),
cmd_diff_index() does not do that, either, so I assumed that nobody
has converted run_diff_index() yet.  And that was where my question
came from.

Thanks.

Re: [PATCH] describe: enable sparse index for describe

[Derrick Stolee]

On 3/28/23 4:24 PM, Junio C Hamano wrote:
> Derrick Stolee <derrickstolee@github.com> writes:
> 
>>>>  			setup_work_tree();
>>>> +			prepare_repo_settings(the_repository);
>>>> +			the_repository->settings.command_requires_full_index = 0;
>>>
>>> Offhand, the only case I know that "describe" even _needs_ a working
>>> tree or the index is when asked to do the "--dirty" thing.  To
>>> figure out if the working tree files are modified, the code calls
>>> into run_diff_index(), but has that codepath been made sparse-index
>>> aware already?
>>
>> It seems that this is a case where we can rely on the existing
>> changes around run_diff_index(), which is nice. We get a very
>> easy win for a narrow case.
> 
> Hmph, so "diff-index" is already sparse-index aware?  I looked for
> any old commit that flips .command_requires_full_index to false for
> the command and didn't find it, and if I recall correctly (I only
> checked when I wrote the comment you are responding to),
> cmd_diff_index() does not do that, either, so I assumed that nobody
> has converted run_diff_index() yet.  And that was where my question
> came from.

Since 'git diff --cached' is covered as of 51ba65b5c35 (diff:
enable and test the sparse index, 2021-12-06), that means that
the implementation run_diff_index() is covered.

In fact, it's likely that the reason it's covered is because
run_diff_index() calls diff_cache() which calls unpack_trees() and
unpack_trees() needs to work for _anything_ to work, especially
'git status' and 'git checkout'.

The only thing keeping us from enabling the sparse index on many
of these "diff" builtins is the necessary testing in t1092. I'm
sure that diff-index is very easy to convert. Hopefully, we will
have a GSoC student this summer who can tackle most of these easy
ones, as well as a tricky one or two.

Thanks,
-Stolee

[PATCH v2] describe: enable sparse index for describe

[Raghul Nanth A via GitGitGadget]

From: Raghul Nanth A <nanth.raghul@gmail.com>

Add usage and performance tests for describe

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---
    describe: enable sparse index for describe
    
     * Removed describe tests not concerned with sparse index
    
     * Added performance metric to commit message

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1480%2FNanthR%2Fdescribe-sparse-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1480/NanthR/describe-sparse-v2
Pull-Request: https://github.com/git/git/pull/1480

Range-diff vs v1:

 1:  4689f6512db ! 1:  03176f64607 describe: enable sparse index for describe
     @@ Commit message
      
          Add usage and performance tests for describe
      
     +    Performance metrics
     +
     +      Test                                                     HEAD~1            HEAD
     +      -------------------------------------------------------------------------------------------------
     +      2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
     +      2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
     +      2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
     +      2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
     +      2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
     +      2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
     +      2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
     +      2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%
     +
          Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
      
       ## builtin/describe.c ##
     @@ builtin/describe.c: int cmd_describe(int argc, const char **argv, const char *pr
      
       ## t/perf/p2000-sparse-operations.sh ##
      @@ t/perf/p2000-sparse-operations.sh: test_expect_success 'setup repo and indexes' '
     - 		git sparse-checkout set $SPARSE_CONE &&
     - 		git config index.version 3 &&
     - 		git update-index --index-version=3 &&
     --		git checkout HEAD~4
     -+		git checkout HEAD~4 &&
     -+		git tag -a v1.0 -m "Final"
     - 	) &&
     - 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-v4 &&
     - 	(
     -@@ t/perf/p2000-sparse-operations.sh: test_expect_success 'setup repo and indexes' '
     - 		git sparse-checkout set $SPARSE_CONE &&
     - 		git config index.version 4 &&
     - 		git update-index --index-version=4 &&
     --		git checkout HEAD~4
     -+		git checkout HEAD~4 &&
     -+		git tag -a v1.0 -m "Final"
     - 	) &&
     - 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v3 &&
     - 	(
     -@@ t/perf/p2000-sparse-operations.sh: test_expect_success 'setup repo and indexes' '
     - 		git sparse-checkout set $SPARSE_CONE &&
     - 		git config index.version 3 &&
     - 		git update-index --index-version=3 &&
     --		git checkout HEAD~4
     -+		git checkout HEAD~4 &&
     -+		git tag -a v1.0 -m "Final"
     - 	) &&
     - 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-v4 &&
     - 	(
     -@@ t/perf/p2000-sparse-operations.sh: test_expect_success 'setup repo and indexes' '
     - 		git sparse-checkout set $SPARSE_CONE &&
     - 		git config index.version 4 &&
     - 		git update-index --index-version=4 &&
     --		git checkout HEAD~4
     -+		git checkout HEAD~4 &&
     -+		git tag -a v1.0 -m "Final"
     - 	)
     - '
     + 	done &&
     + 
     + 	git sparse-checkout init --cone &&
     ++	git tag -a v1.0 -m "Final" &&
     + 	git sparse-checkout set $SPARSE_CONE &&
     + 	git checkout -b wide $OLD_COMMIT &&
       
      @@ t/perf/p2000-sparse-operations.sh: test_perf_on_all git checkout-index -f --all
       test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
       test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
       test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
      +test_perf_on_all git describe --dirty
     -+test_perf_on_all 'echo >> new && git describe --dirty'
     ++test_perf_on_all 'echo >>new && git describe --dirty'
       
       test_done
      
     @@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'sparse-index is n
       
      +test_expect_success 'sparse-index is not expanded: describe' '
      +	init_repos &&
     ++	# Add tag to be read by describe
      +	ensure_not_expanded tag -a v1.0 -m "Version 1" &&
      +	ensure_not_expanded describe --dirty &&
      +	ensure_not_expanded describe &&
     -+	echo "test" >> sparse-index/extra.txt &&
     ++	echo "test" >>sparse-index/extra.txt &&
      +	ensure_not_expanded describe --dirty &&
      +	ensure_not_expanded describe
      +'
     @@ t/t6121-describe-sparse.sh (new)
      +
      +test_description='git describe in sparse checked out trees'
      +
     -+#  o---o-----o----o----o-------o----x
     -+#       \   D,R   e           /
     -+#        \---o-------------o-'
     -+#         \  B            /
     -+#          `-o----o----o-'
     -+#                 A    c
     -+#
     -+# First parent of a merge commit is on the same line, second parent below.
     -+
      +GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
      +export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
      +
     @@ t/t6121-describe-sparse.sh (new)
      +	shift
      +	describe_opts="$@"
      +	test_expect_success "describe $describe_opts" '
     -+		git ${indir:+ -C "$indir"} describe $describe_opts >raw &&
     -+		sed -e "s/-g[0-9a-f]*\$/-gHASH/" <raw >actual &&
     ++		git ${indir:+ -C "$indir"} describe $describe_opts >actual &&
      +		echo "$expect" >expect &&
      +		test_cmp expect actual
      +	'
     @@ t/t6121-describe-sparse.sh (new)
      +
      +test_expect_success setup '
      +	test_commit initial file one &&
     -+	test_commit second file two &&
     -+	test_commit third file three &&
      +	test_commit --annotate A file A &&
     -+	test_commit c file c &&
     -+
     -+	git reset --hard second &&
     -+	test_commit --annotate B side B &&
     -+
     -+	test_tick &&
     -+	git merge -m Merged c &&
     -+	merged=$(git rev-parse HEAD) &&
     -+
     -+	git reset --hard second &&
     -+	test_commit --no-tag D another D &&
      +
      +	test_tick &&
     -+	git tag -a -m R R &&
      +
     -+	test_commit e another DD &&
     -+	test_commit --no-tag "yet another" another DDD &&
     -+
     -+	test_tick &&
     -+	git merge -m Merged $merged &&
     -+
     -+	test_commit --no-tag x file &&
      +	git sparse-checkout init --cone
      +'
      +
     -+check_describe A-8-gHASH HEAD
     -+check_describe A-7-gHASH HEAD^
     -+check_describe R-2-gHASH HEAD^^
     -+check_describe A-3-gHASH HEAD^^2
     -+check_describe B HEAD^^2^
     -+check_describe R-1-gHASH HEAD^^^
     -+
     -+check_describe c-7-gHASH --tags HEAD
     -+check_describe c-6-gHASH --tags HEAD^
     -+check_describe e-1-gHASH --tags HEAD^^
     -+check_describe c-2-gHASH --tags HEAD^^2
     -+check_describe B --tags HEAD^^2^
     -+check_describe e --tags HEAD^^^
     -+
     -+check_describe heads/main --all HEAD
     -+check_describe tags/c-6-gHASH --all HEAD^
     -+check_describe tags/e --all HEAD^^^
     -+
     -+check_describe B-0-gHASH --long HEAD^^2^
     -+check_describe A-3-gHASH --long HEAD^^2
     -+
     -+check_describe c-7-gHASH --tags
     -+check_describe e-3-gHASH --first-parent --tags
     -+
     -+test_expect_success 'describe --contains defaults to HEAD without commit-ish' '
     -+	echo "A^0" >expect &&
     -+	git checkout A &&
     -+	test_when_finished "git checkout -" &&
     -+	git describe --contains >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+check_describe tags/A --all A^0
     -+
     -+test_expect_success 'renaming tag A to Q locally produces a warning' "
     -+	git update-ref refs/tags/Q $(git rev-parse refs/tags/A) &&
     -+	git update-ref -d refs/tags/A &&
     -+	git describe HEAD 2>err >out &&
     -+	cat >expected <<-\EOF &&
     -+	warning: tag 'Q' is externally known as 'A'
     -+	EOF
     -+	test_cmp expected err &&
     -+	grep -E '^A-8-g[0-9a-f]+$' out
     -+"
     -+
     -+test_expect_success 'misnamed annotated tag forces long output' '
     -+	description=$(git describe --no-long Q^0) &&
     -+	expr "$description" : "A-0-g[0-9a-f]*$" &&
     -+	git rev-parse --verify "$description" >actual &&
     -+	git rev-parse --verify Q^0 >expect &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'abbrev=0 will not break misplaced tag (1)' '
     -+	description=$(git describe --abbrev=0 Q^0) &&
     -+	expr "$description" : "A-0-g[0-9a-f]*$"
     -+'
     -+
     -+test_expect_success 'abbrev=0 will not break misplaced tag (2)' '
     -+	description=$(git describe --abbrev=0 c^0) &&
     -+	expr "$description" : "A-1-g[0-9a-f]*$"
     -+'
     -+
     -+test_expect_success 'rename tag Q back to A' '
     -+	git update-ref refs/tags/A $(git rev-parse refs/tags/Q) &&
     -+	git update-ref -d refs/tags/Q
     -+'
     -+
     -+test_expect_success 'pack tag refs' 'git pack-refs'
     -+check_describe A-8-gHASH HEAD
     -+
     -+test_expect_success 'describe works from outside repo using --git-dir' '
     -+	git clone --bare "$TRASH_DIRECTORY" "$TRASH_DIRECTORY/bare" &&
     -+	git --git-dir "$TRASH_DIRECTORY/bare" describe >out &&
     -+	grep -E "^A-8-g[0-9a-f]+$" out
     -+'
     -+
     -+check_describe "A-8-gHASH" --dirty
     ++check_describe A HEAD
      +
      +test_expect_success 'describe --dirty with --work-tree' '
      +	(
      +		cd "$TEST_DIRECTORY" &&
      +		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
      +	) &&
     -+	grep -E "^A-8-g[0-9a-f]+$" out
     ++	grep "A" out
      +'
      +
      +test_expect_success 'set-up dirty work tree' '
     @@ t/t6121-describe-sparse.sh (new)
      +		cd "$TEST_DIRECTORY" &&
      +		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
      +	) &&
     -+	grep -E "^A-8-g[0-9a-f]+-dirty$" out &&
     -+	test_cmp expected out
     -+'
     -+
     -+test_expect_success 'describe --dirty=.mod with --work-tree (dirty)' '
     -+	git describe --dirty=.mod >expected &&
     -+	(
     -+		cd "$TEST_DIRECTORY" &&
     -+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty=.mod >"$TRASH_DIRECTORY/out"
     -+	) &&
     -+	grep -E "^A-8-g[0-9a-f]+.mod$" out &&
      +	test_cmp expected out
      +'
     -+
     -+test_expect_success 'describe --dirty HEAD' '
     -+	test_must_fail git describe --dirty HEAD
     -+'
     -+
     -+test_expect_success 'set-up matching pattern tests' '
     -+	git tag -a -m test-annotated test-annotated &&
     -+	echo >>file &&
     -+	test_tick &&
     -+	git commit -a -m "one more" &&
     -+	git tag test1-lightweight &&
     -+	echo >>file &&
     -+	test_tick &&
     -+	git commit -a -m "yet another" &&
     -+	git tag test2-lightweight &&
     -+	echo >>file &&
     -+	test_tick &&
     -+	git commit -a -m "even more"
     -+
     -+'
     -+
     -+check_describe "test-annotated-3-gHASH" --match="test-*"
     -+
     -+check_describe "test1-lightweight-2-gHASH" --tags --match="test1-*"
     -+
     -+check_describe "test2-lightweight-1-gHASH" --tags --match="test2-*"
     -+
     -+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test2-*" HEAD^
     -+
     -+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test1-*" --match="test2-*" HEAD^
     -+
     -+check_describe "test2-lightweight-0-gHASH" --long --tags --match="test1-*" --no-match --match="test2-*" HEAD^
     -+
     -+check_describe "test1-lightweight-2-gHASH" --long --tags --match="test1-*" --match="test3-*" HEAD
     -+
     -+check_describe "test1-lightweight-2-gHASH" --long --tags --match="test3-*" --match="test1-*" HEAD
     -+
     -+test_expect_success 'set-up branches' '
     -+	git branch branch_A A &&
     -+	git branch branch_C c &&
     -+	git update-ref refs/remotes/origin/remote_branch_A "A^{commit}" &&
     -+	git update-ref refs/remotes/origin/remote_branch_C "c^{commit}" &&
     -+	git update-ref refs/original/original_branch_A test-annotated~2
     -+'
     -+
     -+check_describe "heads/branch_A-11-gHASH" --all --match="branch_*" --exclude="branch_C" HEAD
     -+
     -+check_describe "remotes/origin/remote_branch_A-11-gHASH" --all --match="origin/remote_branch_*" --exclude="origin/remote_branch_C" HEAD
     -+
     -+check_describe "original/original_branch_A-6-gHASH" --all test-annotated~1
     -+
     -+test_expect_success '--match does not work for other types' '
     -+	test_must_fail git describe --all --match="*original_branch_*" test-annotated~1
     -+'
     -+
     -+test_expect_success '--exclude does not work for other types' '
     -+	R=$(git describe --all --exclude="any_pattern_even_not_matching" test-annotated~1) &&
     -+	case "$R" in
     -+	*original_branch_A*) echo "fail: Found unknown reference $R with --exclude"
     -+		false;;
     -+	*) echo ok: Found some known type;;
     -+	esac
     -+'
     -+
     -+test_expect_success 'name-rev with exact tags' '
     -+	echo A >expect &&
     -+	tag_object=$(git rev-parse refs/tags/A) &&
     -+	git name-rev --tags --name-only $tag_object >actual &&
     -+	test_cmp expect actual &&
     -+
     -+	echo "A^0" >expect &&
     -+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
     -+	git name-rev --tags --name-only $tagged_commit >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'name-rev --all' '
     -+	>expect.unsorted &&
     -+	for rev in $(git rev-list --all)
     -+	do
     -+		git name-rev $rev >>expect.unsorted || return 1
     -+	done &&
     -+	sort <expect.unsorted >expect &&
     -+	git name-rev --all >actual.unsorted &&
     -+	sort <actual.unsorted >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'name-rev --annotate-stdin' '
     -+	>expect.unsorted &&
     -+	for rev in $(git rev-list --all)
     -+	do
     -+		name=$(git name-rev --name-only $rev) &&
     -+		echo "$rev ($name)" >>expect.unsorted || return 1
     -+	done &&
     -+	sort <expect.unsorted >expect &&
     -+	git rev-list --all | git name-rev --annotate-stdin >actual.unsorted &&
     -+	sort <actual.unsorted >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'name-rev --stdin deprecated' "
     -+	git rev-list --all | git name-rev --stdin 2>actual &&
     -+	grep -E 'warning: --stdin is deprecated' actual
     -+"
     -+
     -+test_expect_success 'describe --contains with the exact tags' '
     -+	echo "A^0" >expect &&
     -+	tag_object=$(git rev-parse refs/tags/A) &&
     -+	git describe --contains $tag_object >actual &&
     -+	test_cmp expect actual &&
     -+
     -+	echo "A^0" >expect &&
     -+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
     -+	git describe --contains $tagged_commit >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe --contains and --match' '
     -+	echo "A^0" >expect &&
     -+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
     -+	test_must_fail git describe --contains --match="B" $tagged_commit &&
     -+	git describe --contains --match="B" --match="A" $tagged_commit >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe --exclude' '
     -+	echo "c~1" >expect &&
     -+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
     -+	test_must_fail git describe --contains --match="B" $tagged_commit &&
     -+	git describe --contains --match="?" --exclude="A" $tagged_commit >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe --contains and --no-match' '
     -+	echo "A^0" >expect &&
     -+	tagged_commit=$(git rev-parse "refs/tags/A^0") &&
     -+	git describe --contains --match="B" --no-match $tagged_commit >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'setup and absorb a submodule' '
     -+	git init sub1 &&
     -+	test_commit -C sub1 initial &&
     -+	git sparse-checkout add sub1 &&
     -+	git submodule add ./sub1 &&
     -+	git submodule absorbgitdirs &&
     -+	git commit -a -m "add submodule" &&
     -+	git describe --dirty >expect &&
     -+	git describe --broken >out &&
     -+	test_cmp expect out
     -+'
     -+
     -+test_expect_success 'describe chokes on severely broken submodules' '
     -+	mv .git/modules/sub1/ .git/modules/sub_moved &&
     -+	test_must_fail git describe --dirty
     -+'
     -+
     -+test_expect_success 'describe ignoring a broken submodule' '
     -+	git describe --broken >out &&
     -+	grep broken out
     -+'
     -+
     -+test_expect_success 'describe with --work-tree ignoring a broken submodule' '
     -+	(
     -+		cd "$TEST_DIRECTORY" &&
     -+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --broken >"$TRASH_DIRECTORY/out"
     -+	) &&
     -+	test_when_finished "mv .git/modules/sub_moved .git/modules/sub1" &&
     -+	grep broken out
     -+'
     -+
     -+test_expect_success 'describe a blob at a directly tagged commit' '
     -+	echo "make it a unique blob" >file &&
     -+	git add file && git commit -m "content in file" &&
     -+	git tag -a -m "latest annotated tag" unique-file &&
     -+	git describe HEAD:file >actual &&
     -+	echo "unique-file:file" >expect &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe a blob with its first introduction' '
     -+	git commit --allow-empty -m "empty commit" &&
     -+	git rm file &&
     -+	git commit -m "delete blob" &&
     -+	git revert HEAD &&
     -+	git commit --allow-empty -m "empty commit" &&
     -+	git describe HEAD:file >actual &&
     -+	echo "unique-file:file" >expect &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe directly tagged blob' '
     -+	git tag test-blob unique-file:file &&
     -+	git describe test-blob >actual &&
     -+	echo "unique-file:file" >expect &&
     -+	# suboptimal: we rather want to see "test-blob"
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success 'describe tag object' '
     -+	git tag test-blob-1 -a -m msg unique-file:file &&
     -+	test_must_fail git describe test-blob-1 2>actual &&
     -+	test_i18ngrep "fatal: test-blob-1 is neither a commit nor blob" actual
     -+'
     -+
     -+test_expect_success ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '
     -+	i=1 &&
     -+	while test $i -lt 8000
     -+	do
     -+		echo "commit refs/heads/main
     -+committer A U Thor <author@example.com> $((1000000000 + $i * 100)) +0200
     -+data <<EOF
     -+commit #$i
     -+EOF" &&
     -+		if test $i = 1
     -+		then
     -+			echo "from refs/heads/main^0"
     -+		fi &&
     -+		i=$(($i + 1)) || return 1
     -+	done | git fast-import &&
     -+	git checkout main &&
     -+	git tag far-far-away HEAD^ &&
     -+	echo "HEAD~4000 tags/far-far-away~3999" >expect &&
     -+	git name-rev HEAD~4000 >actual &&
     -+	test_cmp expect actual &&
     -+	run_with_limited_stack git name-rev HEAD~4000 >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+test_expect_success ULIMIT_STACK_SIZE 'describe works in a deep repo' '
     -+	git tag -f far-far-away HEAD~7999 &&
     -+	echo "far-far-away" >expect &&
     -+	git describe --tags --abbrev=0 HEAD~4000 >actual &&
     -+	test_cmp expect actual &&
     -+	run_with_limited_stack git describe --tags --abbrev=0 HEAD~4000 >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+check_describe tags/A --all A
     -+check_describe tags/c --all c
     -+check_describe heads/branch_A --all --match='branch_*' branch_A
     -+
     -+test_expect_success 'describe complains about tree object' '
     -+	test_must_fail git describe HEAD^{tree}
     -+'
     -+
     -+test_expect_success 'describe complains about missing object' '
     -+	test_must_fail git describe $ZERO_OID
     -+'
     -+
     -+test_expect_success 'name-rev a rev shortly after epoch' '
     -+	test_when_finished "git checkout main" &&
     -+
     -+	git checkout --orphan no-timestamp-underflow &&
     -+	# Any date closer to epoch than the CUTOFF_DATE_SLOP constant
     -+	# in builtin/name-rev.c.
     -+	GIT_COMMITTER_DATE="@1234 +0000" \
     -+	git commit -m "committer date shortly after epoch" &&
     -+	old_commit_oid=$(git rev-parse HEAD) &&
     -+
     -+	echo "$old_commit_oid no-timestamp-underflow" >expect &&
     -+	git name-rev $old_commit_oid >actual &&
     -+	test_cmp expect actual
     -+'
     -+
     -+# A--------------main
     -+#  \            /
     -+#   \----------M2
     -+#    \        /
     -+#     \---M1-C
     -+#      \ /
     -+#       B
     -+test_expect_success 'name-rev covers all conditions while looking at parents' '
     -+	git init repo &&
     -+	(
     -+		cd repo &&
     -+
     -+		echo A >file &&
     -+		git add file &&
     -+		git commit -m A &&
     -+		A=$(git rev-parse HEAD) &&
     -+
     -+		git checkout --detach &&
     -+		echo B >file &&
     -+		git commit -m B file &&
     -+		B=$(git rev-parse HEAD) &&
     -+
     -+		git checkout $A &&
     -+		git merge --no-ff $B &&  # M1
     -+
     -+		echo C >file &&
     -+		git commit -m C file &&
     -+
     -+		git checkout $A &&
     -+		git merge --no-ff HEAD@{1} && # M2
     -+
     -+		git checkout main &&
     -+		git merge --no-ff HEAD@{1} &&
     -+
     -+		echo "$B main^2^2~1^2" >expect &&
     -+		git name-rev $B >actual &&
     -+
     -+		test_cmp expect actual &&
     -+		git sparse-checkout init --cone
     -+	)
     -+'
     -+
     -+# A-B-C-D-E-main
     -+#
     -+# Where C has a non-monotonically increasing commit timestamp w.r.t. other
     -+# commits
     -+test_expect_success 'non-monotonic commit dates setup' '
     -+	UNIX_EPOCH_ZERO="@0 +0000" &&
     -+	git init non-monotonic &&
     -+	test_commit -C non-monotonic A &&
     -+	test_commit -C non-monotonic --no-tag B &&
     -+	test_commit -C non-monotonic --no-tag --date "$UNIX_EPOCH_ZERO" C &&
     -+	test_commit -C non-monotonic D &&
     -+	test_commit -C non-monotonic E &&
     -+	(
     -+		cd non-monotonic &&
     -+		git sparse-checkout init --cone
     -+	)
     -+'
     -+
     -+test_expect_success 'name-rev with commitGraph handles non-monotonic timestamps' '
     -+	test_config -C non-monotonic core.commitGraph true &&
     -+	(
     -+		cd non-monotonic &&
     -+
     -+		git commit-graph write --reachable &&
     -+
     -+		echo "main~3 tags/D~2" >expect &&
     -+		git name-rev --tags main~3 >actual &&
     -+
     -+		test_cmp expect actual
     -+	)
     -+'
     -+
     -+test_expect_success 'name-rev --all works with non-monotonic timestamps' '
     -+	test_config -C non-monotonic core.commitGraph false &&
     -+	(
     -+		cd non-monotonic &&
     -+
     -+		rm -rf .git/info/commit-graph* &&
     -+
     -+		cat >tags <<-\EOF &&
     -+		tags/E
     -+		tags/D
     -+		tags/D~1
     -+		tags/D~2
     -+		tags/A
     -+		EOF
     -+
     -+		git log --pretty=%H >revs &&
     -+
     -+		paste -d" " revs tags | sort >expect &&
     -+
     -+		git name-rev --tags --all | sort >actual &&
     -+		test_cmp expect actual
     -+	)
     -+'
     -+
     -+test_expect_success 'name-rev --annotate-stdin works with non-monotonic timestamps' '
     -+	test_config -C non-monotonic core.commitGraph false &&
     -+	(
     -+		cd non-monotonic &&
     -+
     -+		rm -rf .git/info/commit-graph* &&
     -+
     -+		cat >expect <<-\EOF &&
     -+		E
     -+		D
     -+		D~1
     -+		D~2
     -+		A
     -+		EOF
     -+
     -+		git log --pretty=%H >revs &&
     -+		git name-rev --tags --annotate-stdin --name-only <revs >actual &&
     -+		test_cmp expect actual
     -+	)
     -+'
     -+
     -+test_expect_success 'name-rev --all works with commitGraph' '
     -+	test_config -C non-monotonic core.commitGraph true &&
     -+	(
     -+		cd non-monotonic &&
     -+
     -+		git commit-graph write --reachable &&
     -+
     -+		cat >tags <<-\EOF &&
     -+		tags/E
     -+		tags/D
     -+		tags/D~1
     -+		tags/D~2
     -+		tags/A
     -+		EOF
     -+
     -+		git log --pretty=%H >revs &&
     -+
     -+		paste -d" " revs tags | sort >expect &&
     -+
     -+		git name-rev --tags --all | sort >actual &&
     -+		test_cmp expect actual
     -+	)
     -+'
     -+
     -+test_expect_success 'name-rev --annotate-stdin works with commitGraph' '
     -+	test_config -C non-monotonic core.commitGraph true &&
     -+	(
     -+		cd non-monotonic &&
     -+
     -+		git commit-graph write --reachable &&
     -+
     -+		cat >expect <<-\EOF &&
     -+		E
     -+		D
     -+		D~1
     -+		D~2
     -+		A
     -+		EOF
     -+
     -+		git log --pretty=%H >revs &&
     -+		git name-rev --tags --annotate-stdin --name-only <revs >actual &&
     -+		test_cmp expect actual
     -+	)
     -+'
     -+
     -+#               B
     -+#               o
     -+#                \
     -+#  o-----o---o----x
     -+#        A
     -+#
     -+test_expect_success 'setup: describe commits with disjoint bases' '
     -+	git init disjoint1 &&
     -+	(
     -+		cd disjoint1 &&
     -+
     -+		echo o >> file && git add file && git commit -m o &&
     -+		echo A >> file && git add file && git commit -m A &&
     -+		git tag A -a -m A &&
     -+		echo o >> file && git add file && git commit -m o &&
     -+
     -+		git checkout --orphan branch && rm file &&
     -+		echo B > file2 && git add file2 && git commit -m B &&
     -+		git tag B -a -m B &&
     -+		git merge --no-ff --allow-unrelated-histories main -m x &&
     -+		git sparse-checkout init --cone
     -+	)
     -+'
     -+
     -+check_describe -C disjoint1 "A-3-gHASH" HEAD
     -+
     -+#           B
     -+#   o---o---o------------.
     -+#                         \
     -+#                  o---o---x
     -+#                  A
     -+#
     -+test_expect_success 'setup: describe commits with disjoint bases 2' '
     -+	git init disjoint2 &&
     -+	(
     -+		cd disjoint2 &&
     -+
     -+		echo A >> file && git add file && GIT_COMMITTER_DATE="2020-01-01 18:00" git commit -m A &&
     -+		git tag A -a -m A &&
     -+		echo o >> file && git add file && GIT_COMMITTER_DATE="2020-01-01 18:01" git commit -m o &&
     -+
     -+		git checkout --orphan branch &&
     -+		echo o >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:00" git commit -m o &&
     -+		echo o >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:01" git commit -m o &&
     -+		echo B >> file2 && git add file2 && GIT_COMMITTER_DATE="2020-01-01 15:02" git commit -m B &&
     -+		git tag B -a -m B &&
     -+		git merge --no-ff --allow-unrelated-histories main -m x &&
     -+		git sparse-checkout init --cone
     -+	)
     -+'
     -+
     -+check_describe -C disjoint2 "B-3-gHASH" HEAD
     -+
     -+test_expect_success 'setup misleading taggerdates' '
     -+	GIT_COMMITTER_DATE="2006-12-12 12:31" git tag -a -m "another tag" newer-tag-older-commit unique-file~1
     -+'
     -+
     -+check_describe newer-tag-older-commit~1 --contains unique-file~2
     -+
      +test_done


 builtin/describe.c                       |  2 +
 t/perf/p2000-sparse-operations.sh        |  3 ++
 t/t1092-sparse-checkout-compatibility.sh | 11 ++++
 t/t6121-describe-sparse.sh               | 67 ++++++++++++++++++++++++
 4 files changed, 83 insertions(+)
 create mode 100755 t/t6121-describe-sparse.sh

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8c..7ff9b5e4b20 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a0..db7887470f9 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e1..9a4db09178f 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,17 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+	# Add tag to be read by describe
+	ensure_not_expanded tag -a v1.0 -m "Version 1" &&
+	ensure_not_expanded describe --dirty &&
+	ensure_not_expanded describe &&
+	echo "test" >>sparse-index/extra.txt &&
+	ensure_not_expanded describe --dirty &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
diff --git a/t/t6121-describe-sparse.sh b/t/t6121-describe-sparse.sh
new file mode 100755
index 00000000000..ce53603c387
--- /dev/null
+++ b/t/t6121-describe-sparse.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+
+test_description='git describe in sparse checked out trees'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+check_describe () {
+	indir= &&
+	while test $# != 0
+	do
+		case "$1" in
+		-C)
+			indir="$2"
+			shift
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done &&
+	indir=${indir:+"$indir"/} &&
+	expect="$1"
+	shift
+	describe_opts="$@"
+	test_expect_success "describe $describe_opts" '
+		git ${indir:+ -C "$indir"} describe $describe_opts >actual &&
+		echo "$expect" >expect &&
+		test_cmp expect actual
+	'
+}
+
+test_expect_success setup '
+	test_commit initial file one &&
+	test_commit --annotate A file A &&
+
+	test_tick &&
+
+	git sparse-checkout init --cone
+'
+
+check_describe A HEAD
+
+test_expect_success 'describe --dirty with --work-tree' '
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	grep "A" out
+'
+
+test_expect_success 'set-up dirty work tree' '
+	echo >>file
+'
+
+test_expect_success 'describe --dirty with --work-tree (dirty)' '
+	git describe --dirty >expected &&
+	(
+		cd "$TEST_DIRECTORY" &&
+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
+	) &&
+	test_cmp expected out
+'
+test_done

base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e
-- 
gitgitgadget

Re: [PATCH v2] describe: enable sparse index for describe

[Junio C Hamano]

"Raghul Nanth A via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Raghul Nanth A <nanth.raghul@gmail.com>
>
> Add usage and performance tests for describe
>
> Performance metrics
> ...

The description is a bit skimpy.  At least it should explain why
blindly flipping the "requires-full-index" bit off is all that is
necessary. I think in the review discussion on v1, Derrick gave some
explanation you can regurgitate and reuse.

> Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
> ...

> diff --git a/t/t6121-describe-sparse.sh b/t/t6121-describe-sparse.sh
> new file mode 100755
> index 00000000000..ce53603c387
> --- /dev/null
> +++ b/t/t6121-describe-sparse.sh
> @@ -0,0 +1,67 @@
> +#!/bin/sh
> +
> +test_description='git describe in sparse checked out trees'
> +
> +GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
> +export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
> +
> +. ./test-lib.sh
> +
> +check_describe () {
> +	indir= &&
> +...
> +	'
> +}

Having this almost identical helper copied from a near-by test
script means maintenance nightmare.  People will forget to side port
to this copy any fixes they make to the other one.

I was hoping there would be a cleaner approach to reuse t6120, by
doing something similar to either how t8001-annotate shares blame
tests, or how t5559 takes advantage of t5551.  One way might be ...

 * prepare a prerequisite like so near the beginning of t6120

	test_lazy_prereq WITH_SPARSE_INDEX '
		test "$TEST_NAME" = t6121-describe
	'

 * add tests to be run with sparse-index enabled, but guarded with
   some variable, e.g.

	test_expect_success TESTING_SPARSE_INDEX 'a new test' '
		... do sparse-index testing specific code ...
	'

   Such "sparse-index testing specific" code may include turning the
   working tree the previous test already prepared into sparse
   (i.e. additional "setup"), or running commands under
   "ensure_not_expanded" (i.e. new tests).

 * create t6121 that works similar to how t5559 takes advantage of
   t5551, something like

	#/bin/sh
	. ./t6120-describe.sh

Ideally we should be able to do this without adding a new t6121, by
adding new tests that are specific to sparse-index at the end of
t6120, and avoid duplicated code.

Another possibility that may take the least amount of effort (but
may give us a lot less satisfactory outcome) may be to add a
lib-describe.sh library that is sourced from t6120 and t6121, and
move check_describe there.  If check_describe has to behave slightly
differently, have a new conditional in the implementation so that
the caller can make a choice.

Re: [PATCH v2] describe: enable sparse index for describe

[Victoria Dye]

Raghul Nanth A via GitGitGadget wrote:
> From: Raghul Nanth A <nanth.raghul@gmail.com>

Hello! Thanks for working on this patch, it's always nice to get more sparse
index support. Since this is your first contribution to the mailing list,
though, it's unclear to me whether you're working on this as an independent
contributor or if you're interested in the Google Summer of Code project
"More Sparse Index Integrations" [1]. If you're doing this for GSoC, could
you please prefix the title of this patch with "[GSoC]" (as noted in the
application details [2])?

On the topic of GSoC applications - if you are submitting this for GSoC, I'm
a bit curious as to why you jumped right into sparse index rather than first
submitting a microproject [3]. This is a good first pass at a sparse index
integration, but the microproject is a better way to get acquainted with the
conventions and requirements of contributing to Git, hence the strong
recommendation to complete one first.

[1] https://git.github.io/SoC-2023-Ideas/
[2] https://git.github.io/General-Application-Information/
[3] https://git.github.io/General-Microproject-Information/

> 
> Add usage and performance tests for describe
> 
> Performance metrics
> 
>   Test                                                     HEAD~1            HEAD
>   -------------------------------------------------------------------------------------------------
>   2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
>   2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
>   2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
>   2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
>   2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
>   2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
>   2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
>   2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

As Junio noted [4], this description doesn't provide much information to a
reader. Commit messages should (at a minimum) explain what the code change
in a commit does, as well as why it's necessary. 

[4] https://lore.kernel.org/git/xmqq355nbii5.fsf@gitster.g/ 

> 
> Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
> ---
>     describe: enable sparse index for describe
>     
>      * Removed describe tests not concerned with sparse index
>     
>      * Added performance metric to commit message
> 
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1480%2FNanthR%2Fdescribe-sparse-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1480/NanthR/describe-sparse-v2
> Pull-Request: https://github.com/git/git/pull/1480
> 
>  builtin/describe.c                       |  2 +
>  t/perf/p2000-sparse-operations.sh        |  3 ++
>  t/t1092-sparse-checkout-compatibility.sh | 11 ++++
>  t/t6121-describe-sparse.sh               | 67 ++++++++++++++++++++++++
>  4 files changed, 83 insertions(+)
>  create mode 100755 t/t6121-describe-sparse.sh
> 
> diff --git a/builtin/describe.c b/builtin/describe.c
> index 5b5930f5c8c..7ff9b5e4b20 100644
> --- a/builtin/describe.c
> +++ b/builtin/describe.c
> @@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
>  			int fd, result;
>  
>  			setup_work_tree();
> +			prepare_repo_settings(the_repository);
> +			the_repository->settings.command_requires_full_index = 0;

Looks good.

>  			repo_read_index(the_repository);
>  			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
>  				      NULL, NULL, NULL);
> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
> index 3242cfe91a0..db7887470f9 100755
> --- a/t/perf/p2000-sparse-operations.sh
> +++ b/t/perf/p2000-sparse-operations.sh
> @@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
>  	done &&
>  
>  	git sparse-checkout init --cone &&
> +	git tag -a v1.0 -m "Final" &&

This isn't disruptive to the existing performance tests, but allows you to
easily test 'git describe'. Nice!

>  	git sparse-checkout set $SPARSE_CONE &&
>  	git checkout -b wide $OLD_COMMIT &&
>  
> @@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>  test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
>  test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
> +test_perf_on_all git describe --dirty
> +test_perf_on_all 'echo >>new && git describe --dirty'
>  
>  test_done
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 801919009e1..9a4db09178f 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1514,6 +1514,17 @@ test_expect_success 'sparse-index is not expanded: stash' '
>  	ensure_not_expanded stash pop
>  '
>  
> +test_expect_success 'sparse-index is not expanded: describe' '
> +	init_repos &&
> +	# Add tag to be read by describe
> +	ensure_not_expanded tag -a v1.0 -m "Version 1" &&

The test you've added isn't verifying the sparse index compatibility of 'git
tag' (which doesn't use the index at all, IIRC), so 'ensure_not_expanded'
isn't needed on this line. You should use 'git -C sparse-index tag ...' to
perform the action instead.

> +	ensure_not_expanded describe --dirty &&
> +	ensure_not_expanded describe &&
> +	echo "test" >>sparse-index/extra.txt &&
> +	ensure_not_expanded describe --dirty &&
> +	ensure_not_expanded describe
> +'
> +
>  test_expect_success 'sparse index is not expanded: diff' '
>  	init_repos &&
>  
> diff --git a/t/t6121-describe-sparse.sh b/t/t6121-describe-sparse.sh
> new file mode 100755
> index 00000000000..ce53603c387
> --- /dev/null
> +++ b/t/t6121-describe-sparse.sh

Is there a specific reason you've created a new test file instead of adding
the tests to 't1092-sparse-checkout-compatibility.sh'? Historically, we've
used 't1092' for validating both the functional correctness of a command
with sparse index enable and the preservation of a sparse index with
'ensure_not_expanded'; you've done the latter in 't1092', but put the former
in this new 't6121'. 't1092' also uses a more "interesting" test repo &
includes comparison functions for full checkout/sparse-checkout/sparse
index, so the tests added for 'git describe' can be more thorough.

> @@ -0,0 +1,67 @@
> +#!/bin/sh
> +
> +test_description='git describe in sparse checked out trees'
> +
> +GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
> +export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
> +
> +. ./test-lib.sh
> +
> +check_describe () {
> +	indir= &&
> +	while test $# != 0
> +	do
> +		case "$1" in
> +		-C)
> +			indir="$2"
> +			shift
> +			;;
> +		*)
> +			break
> +			;;
> +		esac
> +		shift
> +	done &&
> +	indir=${indir:+"$indir"/} &&
> +	expect="$1"
> +	shift
> +	describe_opts="$@"
> +	test_expect_success "describe $describe_opts" '
> +		git ${indir:+ -C "$indir"} describe $describe_opts >actual &&
> +		echo "$expect" >expect &&
> +		test_cmp expect actual
> +	'
> +}
> +
> +test_expect_success setup '
> +	test_commit initial file one &&
> +	test_commit --annotate A file A &&
> +
> +	test_tick &&
> +
> +	git sparse-checkout init --cone
> +'
> +
> +check_describe A HEAD
> +
> +test_expect_success 'describe --dirty with --work-tree' '
> +	(
> +		cd "$TEST_DIRECTORY" &&
> +		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
> +	) &&
> +	grep "A" out
> +'
> +
> +test_expect_success 'set-up dirty work tree' '
> +	echo >>file
> +'
> +
> +test_expect_success 'describe --dirty with --work-tree (dirty)' '
> +	git describe --dirty >expected &&
> +	(
> +		cd "$TEST_DIRECTORY" &&
> +		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
> +	) &&
> +	test_cmp expected out
> +'
> +test_done
> 
> base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e

Re: [PATCH v2] describe: enable sparse index for describe

[Junio C Hamano]

Victoria Dye <vdye@github.com> writes:

>> diff --git a/t/t6121-describe-sparse.sh b/t/t6121-describe-sparse.sh
>> new file mode 100755
>> index 00000000000..ce53603c387
>> --- /dev/null
>> +++ b/t/t6121-describe-sparse.sh
>
> Is there a specific reason you've created a new test file instead of adding
> the tests to 't1092-sparse-checkout-compatibility.sh'? Historically, ...
> ... 't1092' also uses a more "interesting" test repo &
> includes comparison functions for full checkout/sparse-checkout/sparse
> index, so the tests added for 'git describe' can be more thorough.

Ahh...  I mentioned t6120 in my response, but t1092 does sound like
a lot more appropriate place for adding tests for these.

Thanks for pointing it out.

Re: [PATCH v2] describe: enable sparse index for describe

[Raghul Nanth]

On 3/29/23 23:19, Victoria Dye wrote:
> Raghul Nanth A via GitGitGadget wrote:
>> From: Raghul Nanth A <nanth.raghul@gmail.com>
> 
> Hello! Thanks for working on this patch, it's always nice to get more sparse
> index support. Since this is your first contribution to the mailing list,
> though, it's unclear to me whether you're working on this as an independent
> contributor or if you're interested in the Google Summer of Code project
> "More Sparse Index Integrations" [1]. If you're doing this for GSoC, could
> you please prefix the title of this patch with "[GSoC]" (as noted in the
> application details [2])?
> 
> On the topic of GSoC applications - if you are submitting this for GSoC, I'm
> a bit curious as to why you jumped right into sparse index rather than first
> submitting a microproject [3]. This is a good first pass at a sparse index
> integration, but the microproject is a better way to get acquainted with the
> conventions and requirements of contributing to Git, hence the strong
> recommendation to complete one first.
> 
> [1] https://git.github.io/SoC-2023-Ideas/
> [2] https://git.github.io/General-Application-Information/
> [3] https://git.github.io/General-Microproject-Information/
> 

Hello. So, yes, I am interested in GSOC. As for the reason for choosing 
to do sparse-index, I had just missed the part about the micro-projects. 
Sorry about that. So, do I submit a micro-project patch?

And as for the changes mentioned, I will make the changes in the title

Re: [PATCH v2] describe: enable sparse index for describe

[Victoria Dye]

Raghul Nanth wrote:
> Hello. So, yes, I am interested in GSOC. As for the reason for choosing to
> do sparse-index, I had just missed the part about the micro-projects.
> Sorry about that. So, do I submit a micro-project patch?

No, you do not need to submit an additional microproject. The 'git describe'
integration covers the intended purpose of a microproject (namely, becoming
familiar with Git contribution best practices).

> 
> And as for the changes mentioned, I will make the changes in the title

[PATCH v3] describe: enable sparse index for describe

[Raghul Nanth A via GitGitGadget]

From: Raghul Nanth A <nanth.raghul@gmail.com>

Add usage and performance tests for describe

Describe uses the index when it is run with --dirty flag, which uses the
run_diff_index commmand. The command is sparse-index aware and hence we
can just set the requires-full-index to false

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---
    describe: enable sparse index for describe
    
     * Removed describe tests not concerned with sparse index
    
     * Added performance metric to commit message
    
     * Moved tests to t1092.sh
    
     * Explained reason for changes in commit message

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1480%2FNanthR%2Fdescribe-sparse-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1480/NanthR/describe-sparse-v3
Pull-Request: https://github.com/git/git/pull/1480

Range-diff vs v2:

 1:  03176f64607 ! 1:  01838ca3ab0 describe: enable sparse index for describe
     @@ Commit message
      
          Add usage and performance tests for describe
      
     +    Describe uses the index when it is run with --dirty flag, which uses the
     +    run_diff_index commmand. The command is sparse-index aware and hence we
     +    can just set the requires-full-index to false
     +
          Performance metrics
      
            Test                                                     HEAD~1            HEAD
     @@ t/t1092-sparse-checkout-compatibility.sh: test_expect_success 'sparse-index is n
      +test_expect_success 'sparse-index is not expanded: describe' '
      +	init_repos &&
      +	# Add tag to be read by describe
     -+	ensure_not_expanded tag -a v1.0 -m "Version 1" &&
     ++	git -C sparse-index tag -a v1.0 -m "Version 1" &&
      +	ensure_not_expanded describe --dirty &&
     ++	cp sparse-index-out sparse-index-dirty &&
      +	ensure_not_expanded describe &&
     -+	echo "test" >>sparse-index/extra.txt &&
     ++	cp sparse-index-out sparse-index-normal &&
     ++	# Check describe has same output on clean tree
     ++	test_cmp sparse-index-dirty sparse-index-normal &&
     ++	echo "test" >>sparse-index/g &&
      +	ensure_not_expanded describe --dirty &&
     ++	echo "v1.0-dirty" > actual &&
     ++	# Check describe on dirty work tree
     ++	test_cmp sparse-index-out actual &&
      +	ensure_not_expanded describe
      +'
      +
       test_expect_success 'sparse index is not expanded: diff' '
       	init_repos &&
       
     -
     - ## t/t6121-describe-sparse.sh (new) ##
     -@@
     -+#!/bin/sh
     -+
     -+test_description='git describe in sparse checked out trees'
     -+
     -+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
     -+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
     -+
     -+. ./test-lib.sh
     -+
     -+check_describe () {
     -+	indir= &&
     -+	while test $# != 0
     -+	do
     -+		case "$1" in
     -+		-C)
     -+			indir="$2"
     -+			shift
     -+			;;
     -+		*)
     -+			break
     -+			;;
     -+		esac
     -+		shift
     -+	done &&
     -+	indir=${indir:+"$indir"/} &&
     -+	expect="$1"
     -+	shift
     -+	describe_opts="$@"
     -+	test_expect_success "describe $describe_opts" '
     -+		git ${indir:+ -C "$indir"} describe $describe_opts >actual &&
     -+		echo "$expect" >expect &&
     -+		test_cmp expect actual
     -+	'
     -+}
     -+
     -+test_expect_success setup '
     -+	test_commit initial file one &&
     -+	test_commit --annotate A file A &&
     -+
     -+	test_tick &&
     -+
     -+	git sparse-checkout init --cone
     -+'
     -+
     -+check_describe A HEAD
     -+
     -+test_expect_success 'describe --dirty with --work-tree' '
     -+	(
     -+		cd "$TEST_DIRECTORY" &&
     -+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
     -+	) &&
     -+	grep "A" out
     -+'
     -+
     -+test_expect_success 'set-up dirty work tree' '
     -+	echo >>file
     -+'
     -+
     -+test_expect_success 'describe --dirty with --work-tree (dirty)' '
     -+	git describe --dirty >expected &&
     -+	(
     -+		cd "$TEST_DIRECTORY" &&
     -+		git --git-dir "$TRASH_DIRECTORY/.git" --work-tree "$TRASH_DIRECTORY" describe --dirty >"$TRASH_DIRECTORY/out"
     -+	) &&
     -+	test_cmp expected out
     -+'
     -+test_done


 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8c..7ff9b5e4b20 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a0..db7887470f9 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e1..8bc35c51426 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,24 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+	# Add tag to be read by describe
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+	ensure_not_expanded describe --dirty &&
+	cp sparse-index-out sparse-index-dirty &&
+	ensure_not_expanded describe &&
+	cp sparse-index-out sparse-index-normal &&
+	# Check describe has same output on clean tree
+	test_cmp sparse-index-dirty sparse-index-normal &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	echo "v1.0-dirty" > actual &&
+	# Check describe on dirty work tree
+	test_cmp sparse-index-out actual &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 

base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e
-- 
gitgitgadget

Re: [PATCH v3] describe: enable sparse index for describe

[Junio C Hamano]

"Raghul Nanth A via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Raghul Nanth A <nanth.raghul@gmail.com>
>
> Add usage and performance tests for describe

I think this sentence can easily go.

> Describe uses the index when it is run with --dirty flag, which uses the
> run_diff_index commmand. The command is sparse-index aware and hence we
> can just set the requires-full-index to false

End the sentence with full-stop.  More importantly, it would be
nicer to have something to substantiate the "this is sparse aware"
claim here, something like "since commit X" or "as shown in the test
tXXXX.YY".

Updated tests do look good, and the code change is of course minimal
and to the point, which is also good.

Thanks.

> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
> index 3242cfe91a0..db7887470f9 100755
> --- a/t/perf/p2000-sparse-operations.sh
> +++ b/t/perf/p2000-sparse-operations.sh
> @@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
>  	done &&
>  
>  	git sparse-checkout init --cone &&
> +	git tag -a v1.0 -m "Final" &&
>  	git sparse-checkout set $SPARSE_CONE &&
>  	git checkout -b wide $OLD_COMMIT &&
>  
> @@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>  test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
>  test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
> +test_perf_on_all git describe --dirty
> +test_perf_on_all 'echo >>new && git describe --dirty'
>  
>  test_done
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 801919009e1..8bc35c51426 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1514,6 +1514,24 @@ test_expect_success 'sparse-index is not expanded: stash' '
>  	ensure_not_expanded stash pop
>  '
>  
> +test_expect_success 'sparse-index is not expanded: describe' '
> +	init_repos &&
> +	# Add tag to be read by describe
> +	git -C sparse-index tag -a v1.0 -m "Version 1" &&
> +	ensure_not_expanded describe --dirty &&
> +	cp sparse-index-out sparse-index-dirty &&
> +	ensure_not_expanded describe &&
> +	cp sparse-index-out sparse-index-normal &&
> +	# Check describe has same output on clean tree
> +	test_cmp sparse-index-dirty sparse-index-normal &&
> +	echo "test" >>sparse-index/g &&
> +	ensure_not_expanded describe --dirty &&
> +	echo "v1.0-dirty" > actual &&
> +	# Check describe on dirty work tree
> +	test_cmp sparse-index-out actual &&
> +	ensure_not_expanded describe
> +'
> +
>  test_expect_success 'sparse index is not expanded: diff' '
>  	init_repos &&
>  
>
> base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e

Re: [PATCH v3] describe: enable sparse index for describe

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> "Raghul Nanth A via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
>> From: Raghul Nanth A <nanth.raghul@gmail.com>
>>
>> Add usage and performance tests for describe
>
> I think this sentence can easily go.
>
>> Describe uses the index when it is run with --dirty flag, which uses the
>> run_diff_index commmand. The command is sparse-index aware and hence we
>> can just set the requires-full-index to false
>
> End the sentence with full-stop.  More importantly, it would be
> nicer to have something to substantiate the "this is sparse aware"
> claim here, something like "since commit X" or "as shown in the test
> tXXXX.YY".

With a bit of digging into the history, I think the topic that was
merged at 8d2c3732 (Merge branch 'ld/sparse-diff-blame', 2021-12-21)
made various modes of "git diff" to be sparse-index aware.  t1092
has tests for "git diff --cached", which uses the same machinery.

    Subject: [PATCH] describe: make it sparse-index aware

    "git describe" needs to compare the index and the working tree
    when (and only when) it is run with the "--dirty" flag.  This is
    done by calling the run_diff_index() function, which has been
    already made aware of the sparse-index in the series that led to
    8d2c3732 (Merge branch 'ld/sparse-diff-blame', 2021-12-21).
    t1092 has tests for "git diff --cached", which uses this exact
    machinery.

    Mark "git describe" that the command does not require the index
    to be expanded fully beforehand.

or something like that.

> Updated tests do look good, and the code change is of course minimal
> and to the point, which is also good.

Thanks.

Re: [PATCH v3] describe: enable sparse index for describe

[Victoria Dye]

Raghul Nanth A via GitGitGadget wrote:
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 801919009e1..8bc35c51426 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1514,6 +1514,24 @@ test_expect_success 'sparse-index is not expanded: stash' '
>  	ensure_not_expanded stash pop
>  '
>  
> +test_expect_success 'sparse-index is not expanded: describe' '
> +	init_repos &&
> +	# Add tag to be read by describe

Please add newlines before these comments to visually space out the test &
make it more readable.

> +	git -C sparse-index tag -a v1.0 -m "Version 1" &&
> +	ensure_not_expanded describe --dirty &&
> +	cp sparse-index-out sparse-index-dirty &&
> +	ensure_not_expanded describe &&
> +	cp sparse-index-out sparse-index-normal &&
> +	# Check describe has same output on clean tree
> +	test_cmp sparse-index-dirty sparse-index-normal &&
> +	echo "test" >>sparse-index/g &&
> +	ensure_not_expanded describe --dirty &&
> +	echo "v1.0-dirty" > actual &&
> +	# Check describe on dirty work tree
> +	test_cmp sparse-index-out actual &&
> +	ensure_not_expanded describe

Sorry if I was unclear in my last review [1], but I did not mean that you
should add cases to this test (and, to be honest, the comparison of
'sparse-index-dirty' and 'sparse-index-normal' doesn't add much here).
Please add separate tests (as in, full 'test_expect_success' blocks) for
checking that the functionality of 'git describe' is consistent across
'full-checkout', 'sparse-checkout', and 'sparse-index'. Past sparse index
integrations ('git grep' [2], 'git read-tree' [3], 'git show' [4], etc.) are
a good reference for the types of tests that should be added.

[1] https://lore.kernel.org/git/8cb2b7a2-78f2-9221-1234-62814557d2d3@github.com/
[2] https://lore.kernel.org/git/20220923041842.27817-2-shaoxuan.yuan02@gmail.com/
[3] https://lore.kernel.org/git/90ebcb7b8ff4b4f1ba09abcbe636d639fa597e74.1646166271.git.gitgitgadget@gmail.com/
[4] https://lore.kernel.org/git/8c2fdb5a4fc3317c05324da54692036e36fc15f3.1651005800.git.gitgitgadget@gmail.com/

> +'
> +
>  test_expect_success 'sparse index is not expanded: diff' '
>  	init_repos &&
>  
> 
> base-commit: 27d43aaaf50ef0ae014b88bba294f93658016a2e

[GSOC][PATCH] describe: enable sparse index for describe

[Raghul Nanth A]

Add usage and performance tests for describe

git describe compares the index with the working tree when (and only
when) it is run with the "--dirty" flag. This is done by the
run_diff_index() function. The function has been made aware of the
sparse-index in the series that led to 8d2c3732 (Merge branch
'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
requires-full-index to false for "describe".

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---
 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 30 ++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8..7ff9b5e4b2 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..db7887470f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..2b46fb2a48 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,36 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'describe tested on all' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	run_on_all git tag -a v1.0 -m "Version 1" &&
+	test_all_match git describe --dirty &&
+	run_on_all rm g &&
+	test_all_match git describe --dirty
+'
+
+
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+
+	ensure_not_expanded describe --dirty &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	echo "v1.0-dirty" >actual &&
+
+	# Check describe on dirty work tree
+
+	test_cmp sparse-index-out actual &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
-- 
2.40.0

As for the previous questions, yes I am intereseted in GSOC. I had
missed the part regarding the micro projects when I was going through
the requirements. Sorry about that. Would I be required to make one now?

Re: [GSOC][PATCH] describe: enable sparse index for describe

[Junio C Hamano]

Raghul Nanth A <nanth.raghul@gmail.com> writes:

> Add usage and performance tests for describe

I think the commit is better off without this line.

> git describe compares the index with the working tree when (and only
> when) it is run with the "--dirty" flag. This is done by the
> ...
>
> Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
> ---

Here is where you describe what got changed since the previous
iteration (and following [PATCH v<N>] notational convention would
help people to see which one is meant to be the latest).  These two
are especially helpful when you send more or less identical patches
in quick succession like within a few hours.

Thanks.

[GSOC][PATCH v4] describe: enable sparse index for describe

[Raghul Nanth A]

git describe compares the index with the working tree when (and only
when) it is run with the "--dirty" flag. This is done by the
run_diff_index() function. The function has been made aware of the
sparse-index in the series that led to 8d2c3732 (Merge branch
'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
requires-full-index to false for "describe".

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---

  * Removed describe tests not concerned with sparse index
  * Added performance metric to commit message
  * Moved tests to t1092.sh
  * Explained reason for changes in commit message
  * Added tests to validate behaviour in sparse and full indices


 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 30 ++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8..7ff9b5e4b2 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..db7887470f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..2b46fb2a48 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,36 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'describe tested on all' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	run_on_all git tag -a v1.0 -m "Version 1" &&
+	test_all_match git describe --dirty &&
+	run_on_all rm g &&
+	test_all_match git describe --dirty
+'
+
+
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+
+	ensure_not_expanded describe --dirty &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	echo "v1.0-dirty" >actual &&
+
+	# Check describe on dirty work tree
+
+	test_cmp sparse-index-out actual &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
-- 
2.40.0

Re: [GSOC][PATCH v4] describe: enable sparse index for describe

[Victoria Dye]

Raghul Nanth A wrote:
> git describe compares the index with the working tree when (and only
> when) it is run with the "--dirty" flag. This is done by the
> run_diff_index() function. The function has been made aware of the
> sparse-index in the series that led to 8d2c3732 (Merge branch
> 'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
> requires-full-index to false for "describe".
> 

This is a good description of the patch and the reasoning behind the
changes.

> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 801919009e..2b46fb2a48 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1514,6 +1514,36 @@ test_expect_success 'sparse-index is not expanded: stash' '
>  	ensure_not_expanded stash pop
>  '
>  
> +test_expect_success 'describe tested on all' '
> +	init_repos &&
> +
> +	# Add tag to be read by describe
> +
> +	run_on_all git tag -a v1.0 -m "Version 1" &&
> +	test_all_match git describe --dirty &&
> +	run_on_all rm g &&
> +	test_all_match git describe --dirty
> +'
> +
> +
> +test_expect_success 'sparse-index is not expanded: describe' '
> +	init_repos &&
> +
> +	# Add tag to be read by describe
> +
> +	git -C sparse-index tag -a v1.0 -m "Version 1" &&
> +
> +	ensure_not_expanded describe --dirty &&
> +	echo "test" >>sparse-index/g &&
> +	ensure_not_expanded describe --dirty &&
> +	echo "v1.0-dirty" >actual &&
> +
> +	# Check describe on dirty work tree
> +
> +	test_cmp sparse-index-out actual &&

This type of output comparison should be part of 'describe tested on all',
not the "ensure not expanded" test; the former tests the correctness of 'git
describe', whereas the latter focuses on index expansion. When unit testing,
it helps to keep the scope of each test fairly narrow with a specific focus
so that they can more easily isolate future regressions.

> +	ensure_not_expanded describe
> +'
> +
>  test_expect_success 'sparse index is not expanded: diff' '
>  	init_repos &&
>  

[GSOC][PATCH v5] describe: enable sparse index for describe

[Raghul Nanth A]

git describe compares the index with the working tree when (and only
when) it is run with the "--dirty" flag. This is done by the
run_diff_index() function. The function has been made aware of the
sparse-index in the series that led to 8d2c3732 (Merge branch
'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
requires-full-index to false for "describe".

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---

  * Removed describe tests not concerned with sparse index
  * Added performance metric to commit message
  * Moved tests to t1092.sh
  * Explained reason for changes in commit message
  * Added tests to validate behaviour in sparse and full indices

 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 25 ++++++++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8..7ff9b5e4b2 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..db7887470f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..51bebd4fa9 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,31 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'describe tested on all' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	run_on_all git tag -a v1.0 -m "Version 1" &&
+	test_all_match git describe --dirty &&
+	run_on_all rm g &&
+	test_all_match git describe --dirty
+'
+
+
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+
+	ensure_not_expanded describe --dirty &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
-- 
2.40.0

[PATCH v4] describe: enable sparse index for describe

[Raghul Nanth A]

git describe compares the index with the working tree when (and only
when) it is run with the "--dirty" flag. This is done by the
run_diff_index() function. The function has been made aware of the
sparse-index in the series that led to 8d2c3732 (Merge branch
'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
requires-full-index to false for "describe".

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---

  * Removed describe tests not concerned with sparse index
  * Added performance metric to commit message
  * Moved tests to t1092.sh
  * Explained reason for changes in commit message
  * Added tests to validate behaviour in sparse and full indices


 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 30 ++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8..7ff9b5e4b2 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..db7887470f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..2b46fb2a48 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,36 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'describe tested on all' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	run_on_all git tag -a v1.0 -m "Version 1" &&
+	test_all_match git describe --dirty &&
+	run_on_all rm g &&
+	test_all_match git describe --dirty
+'
+
+
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+
+	ensure_not_expanded describe --dirty &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	echo "v1.0-dirty" >actual &&
+
+	# Check describe on dirty work tree
+
+	test_cmp sparse-index-out actual &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
-- 
2.40.0

[GSOC][PATCH] describe: enable sparse index for describe

[Raghul Nanth A]

Add usage and performance tests for describe

git describe compares the index with the working tree when (and only
when) it is run with the "--dirty" flag. This is done by the
run_diff_index() function. The function has been made aware of the
sparse-index in the series that led to 8d2c3732 (Merge branch
'ld/sparse-diff-blame', 2021-12-21). Hence we can just set the
requires-full-index to false for "describe".

Performance metrics

  Test                                                     HEAD~1            HEAD
  -------------------------------------------------------------------------------------------------
  2000.2: git describe --dirty (full-v3)                   0.08(0.09+0.01)   0.08(0.06+0.03) +0.0%
  2000.3: git describe --dirty (full-v4)                   0.09(0.07+0.03)   0.08(0.05+0.04) -11.1%
  2000.4: git describe --dirty (sparse-v3)                 0.88(0.82+0.06)   0.02(0.01+0.05) -97.7%
  2000.5: git describe --dirty (sparse-v4)                 0.68(0.60+0.08)   0.02(0.02+0.04) -97.1%
  2000.6: echo >>new && git describe --dirty (full-v3)     0.08(0.04+0.05)   0.08(0.05+0.04) +0.0%
  2000.7: echo >>new && git describe --dirty (full-v4)     0.08(0.07+0.03)   0.08(0.05+0.04) +0.0%
  2000.8: echo >>new && git describe --dirty (sparse-v3)   0.75(0.69+0.07)   0.02(0.03+0.03) -97.3%
  2000.9: echo >>new && git describe --dirty (sparse-v4)   0.81(0.73+0.09)   0.02(0.01+0.05) -97.5%

Signed-off-by: Raghul Nanth A <nanth.raghul@gmail.com>
---
 builtin/describe.c                       |  2 ++
 t/perf/p2000-sparse-operations.sh        |  3 +++
 t/t1092-sparse-checkout-compatibility.sh | 30 ++++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/builtin/describe.c b/builtin/describe.c
index 5b5930f5c8..7ff9b5e4b2 100644
--- a/builtin/describe.c
+++ b/builtin/describe.c
@@ -654,6 +654,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 			int fd, result;
 
 			setup_work_tree();
+			prepare_repo_settings(the_repository);
+			the_repository->settings.command_requires_full_index = 0;
 			repo_read_index(the_repository);
 			refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 				      NULL, NULL, NULL);
diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 3242cfe91a..db7887470f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -43,6 +43,7 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
+	git tag -a v1.0 -m "Final" &&
 	git sparse-checkout set $SPARSE_CONE &&
 	git checkout -b wide $OLD_COMMIT &&
 
@@ -125,5 +126,7 @@ test_perf_on_all git checkout-index -f --all
 test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
 test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
 test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
+test_perf_on_all git describe --dirty
+test_perf_on_all 'echo >>new && git describe --dirty'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index 801919009e..2b46fb2a48 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -1514,6 +1514,36 @@ test_expect_success 'sparse-index is not expanded: stash' '
 	ensure_not_expanded stash pop
 '
 
+test_expect_success 'describe tested on all' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	run_on_all git tag -a v1.0 -m "Version 1" &&
+	test_all_match git describe --dirty &&
+	run_on_all rm g &&
+	test_all_match git describe --dirty
+'
+
+
+test_expect_success 'sparse-index is not expanded: describe' '
+	init_repos &&
+
+	# Add tag to be read by describe
+
+	git -C sparse-index tag -a v1.0 -m "Version 1" &&
+
+	ensure_not_expanded describe --dirty &&
+	echo "test" >>sparse-index/g &&
+	ensure_not_expanded describe --dirty &&
+	echo "v1.0-dirty" >actual &&
+
+	# Check describe on dirty work tree
+
+	test_cmp sparse-index-out actual &&
+	ensure_not_expanded describe
+'
+
 test_expect_success 'sparse index is not expanded: diff' '
 	init_repos &&
 
-- 
2.40.0

As for the previous questions, yes I am intereseted in GSOC. I had
missed the part regarding the micro projects when I was going through
the requirements. Sorry about that. Would I be required to make one now?