Merge branch 'ds/sparse-apply-add-p'

"git apply" and "git add -i/-p" code paths no longer unnecessarily
expand sparse-index while working.

* ds/sparse-apply-add-p:
  p2000: add performance test for patch-mode commands
  reset: integrate sparse index with --patch
  git add: make -p/-i aware of sparse index
  apply: integrate with the sparse index

2 files changed, 154 insertions, 0 deletions

diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
index 39e92b0841..aadf22bc2f 100755
--- a/t/perf/p2000-sparse-operations.sh
+++ b/t/perf/p2000-sparse-operations.sh
@@ -135,5 +135,8 @@ test_perf_on_all git diff-tree HEAD
 test_perf_on_all git diff-tree HEAD -- $SPARSE_CONE/a
 test_perf_on_all "git worktree add ../temp && git worktree remove ../temp"
 test_perf_on_all git check-attr -a -- $SPARSE_CONE/a
+test_perf_on_all 'echo >>a && test_write_lines y | git add -p'
+test_perf_on_all 'test_write_lines y y y | git checkout --patch -'
+test_perf_on_all 'echo >>a && git add a && test_write_lines y | git reset --patch'
 
 test_done
diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
index f9b448792c..d8101139b4 100755
--- a/t/t1092-sparse-checkout-compatibility.sh
+++ b/t/t1092-sparse-checkout-compatibility.sh
@@ -384,6 +384,44 @@ test_expect_success 'add, commit, checkout' '
 	test_all_match git checkout -
 '
 
+test_expect_success 'git add, checkout, and reset with -p' '
+	init_repos &&
+
+	write_script edit-contents <<-\EOF &&
+	echo text >>$1
+	EOF
+
+	# Does not expand when edits are within sparse checkout.
+	run_on_all ../edit-contents deep/a &&
+	run_on_all ../edit-contents deep/deeper1/a &&
+
+	test_write_lines y n >in &&
+	run_on_all git add -p <in &&
+	test_all_match git status --porcelain=v2 &&
+	test_all_match git reset -p <in &&
+
+	test_write_lines u 1 "" q >in &&
+	run_on_all git add -i <in &&
+	test_all_match git status --porcelain=v2 &&
+	test_all_match git reset --hard &&
+
+	run_on_sparse mkdir -p folder1 &&
+	run_on_all ../edit-contents folder1/a &&
+	test_write_lines y n y >in &&
+	run_on_all git add -p <in &&
+	test_sparse_match git status --porcelain=v2 &&
+	test_sparse_match git reset &&
+	test_write_lines u 2 3 "" q >in &&
+	run_on_all git add -i <in &&
+	test_sparse_match git status --porcelain=v2 &&
+
+	run_on_all git add --sparse folder1 &&
+	run_on_all git commit -m "take changes" &&
+	test_write_lines y n y >in &&
+	test_sparse_match git checkout HEAD~1 --patch <in &&
+	test_sparse_match git status --porcelain=v2
+'
+
 test_expect_success 'deep changes during checkout' '
 	init_repos &&
 
@@ -1340,6 +1378,30 @@ test_expect_success 'submodule handling' '
 	grep "160000 $(git -C initial-repo rev-parse HEAD) 0	modules/sub" cache
 '
 
+test_expect_success 'git apply functionality' '
+	init_repos &&
+
+	test_all_match git checkout base &&
+
+	git -C full-checkout diff base..merge-right -- deep >patch-in-sparse &&
+	git -C full-checkout diff base..merge-right -- folder2 >patch-outside &&
+
+	# Apply a patch to a file inside the sparse definition
+	test_all_match git apply --index --stat ../patch-in-sparse &&
+	test_all_match git status --porcelain=v2 &&
+
+	# Apply a patch to a file outside the sparse definition
+	test_sparse_match test_must_fail git apply ../patch-outside &&
+	grep "No such file or directory" sparse-checkout-err &&
+
+	# But it works with --index and --cached
+	test_all_match git apply --index --stat ../patch-outside &&
+	test_all_match git status --porcelain=v2 &&
+	test_all_match git reset --hard &&
+	test_all_match git apply --cached --stat ../patch-outside &&
+	test_all_match git status --porcelain=v2
+'
+
 # When working with a sparse index, some commands will need to expand the
 # index to operate properly. If those commands also write the index back
 # to disk, they need to convert the index to sparse before writing.
@@ -2345,6 +2407,95 @@ test_expect_success 'sparse-index is not expanded: check-attr' '
 	ensure_not_expanded check-attr -a --cached -- folder1/a
 '
 
+test_expect_success 'sparse-index is not expanded: git apply' '
+	init_repos &&
+
+	git -C sparse-index checkout base &&
+	git -C full-checkout diff base..merge-right -- deep >patch-in-sparse &&
+	git -C full-checkout diff base..merge-right -- folder2 >patch-outside &&
+
+	# Apply a patch to a file inside the sparse definition
+	ensure_not_expanded apply --index --stat ../patch-in-sparse &&
+
+	# Apply a patch to a file outside the sparse definition
+	# Fails when caring about the worktree.
+	ensure_not_expanded ! apply ../patch-outside &&
+
+	# Expands when using --index.
+	ensure_expanded apply --index ../patch-outside &&
+
+	# Does not when index is partially expanded.
+	git -C sparse-index reset --hard &&
+	ensure_not_expanded apply --cached ../patch-outside &&
+
+	# Try again with a reset and collapsed index.
+	git -C sparse-index reset --hard &&
+	git -C sparse-index sparse-checkout reapply &&
+
+	# Expands when index is collapsed.
+	ensure_expanded apply --cached ../patch-outside
+'
+
+test_expect_success 'sparse-index is not expanded: git add -p' '
+	init_repos &&
+
+	# Does not expand when edits are within sparse checkout.
+	echo "new content" >sparse-index/deep/a &&
+	echo "new content" >sparse-index/deep/deeper1/a &&
+	test_write_lines y n >in &&
+	ensure_not_expanded add -p <in &&
+	git -C sparse-index reset &&
+	ensure_not_expanded add -i <in &&
+
+	# -p does expand when edits are outside sparse checkout.
+	mkdir -p sparse-index/folder1 &&
+	echo "new content" >sparse-index/folder1/a &&
+	test_write_lines y n y >in &&
+	ensure_expanded add -p <in &&
+
+	# Fully reset the index.
+	git -C sparse-index reset --hard &&
+	git -C sparse-index sparse-checkout reapply &&
+
+	# -i does expand when edits are outside sparse checkout.
+	mkdir -p sparse-index/folder1 &&
+	echo "new content" >sparse-index/folder1/a &&
+	test_write_lines u 2 3 "" q >in &&
+	ensure_expanded add -i <in
+'
+
+test_expect_success 'sparse-index is not expanded: checkout -p, reset -p' '
+	init_repos &&
+
+	# Does not expand when edits are within sparse checkout.
+	echo "new content" >sparse-index/deep/a &&
+	echo "new content" >sparse-index/deep/deeper1/a &&
+	git -C sparse-index commit -a -m "inside-changes" &&
+
+	test_write_lines y y >in &&
+	ensure_not_expanded checkout HEAD~1 --patch <in &&
+
+	echo "new content" >sparse-index/deep/a &&
+	echo "new content" >sparse-index/deep/deeper1/a &&
+	git -C sparse-index add . &&
+	ensure_not_expanded reset --patch <in &&
+
+	# -p does expand when edits are outside sparse checkout.
+	mkdir -p sparse-index/folder1 &&
+	echo "new content" >sparse-index/folder1/a &&
+	git -C sparse-index add --sparse folder1 &&
+	git -C sparse-index sparse-checkout reapply &&
+	ensure_expanded reset --patch <in &&
+
+	# Fully reset the index.
+	mkdir -p sparse-index/folder1 &&
+	echo "new content" >sparse-index/folder1/a &&
+	git -C sparse-index add --sparse folder1 &&
+	git -C sparse-index commit -m "folder1 change" &&
+	git -C sparse-index sparse-checkout reapply &&
+	ensure_expanded checkout HEAD~1 --patch <in
+'
+
 test_expect_success 'advice.sparseIndexExpanded' '
 	init_repos &&